1
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Kim JD, Lee AR, Moon DH, Chung YU, Hong SY, Cho HJ, Kang TH, Jang YH, Sohn MH, Seong BL, Seo SU. Efficacy of genotype-matched vaccine against re-emerging genotype V Japanese encephalitis virus. Emerg Microbes Infect 2024; 13:2343910. [PMID: 38618740 PMCID: PMC11060017 DOI: 10.1080/22221751.2024.2343910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Accepted: 04/11/2024] [Indexed: 04/16/2024]
Abstract
Japanese encephalitis (JE), caused by the Japanese encephalitis virus (JEV), is a highly threatening disease with no specific treatment. Fortunately, the development of vaccines has enabled effective defense against JE. However, re-emerging genotype V (GV) JEV poses a challenge as current vaccines are genotype III (GIII)-based and provide suboptimal protection. Given the isolation of GV JEVs from Malaysia, China, and the Republic of Korea, there is a concern about the potential for a broader outbreak. Under the hypothesis that a GV-based vaccine is necessary for effective defense against GV JEV, we developed a pentameric recombinant antigen using cholera toxin B as a scaffold and mucosal adjuvant, which was conjugated with the E protein domain III of GV by genetic fusion. This GV-based vaccine antigen induced a more effective immune response in mice against GV JEV isolates compared to GIII-based antigen and efficiently protected animals from lethal challenges. Furthermore, a bivalent vaccine approach, inoculating simultaneously with GIII- and GV-based antigens, showed protective efficacy against both GIII and GV JEVs. This strategy presents a promising avenue for comprehensive protection in regions facing the threat of diverse JEV genotypes, including both prevalent GIII and GI as well as emerging GV strains.
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MESH Headings
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/immunology
- Encephalitis Virus, Japanese/classification
- Animals
- Genotype
- Encephalitis, Japanese/prevention & control
- Encephalitis, Japanese/immunology
- Encephalitis, Japanese/virology
- Japanese Encephalitis Vaccines/immunology
- Japanese Encephalitis Vaccines/administration & dosage
- Japanese Encephalitis Vaccines/genetics
- Mice
- Antibodies, Viral/immunology
- Antibodies, Viral/blood
- Humans
- Mice, Inbred BALB C
- Female
- Antigens, Viral/immunology
- Antigens, Viral/genetics
- Vaccine Efficacy
- Cholera Toxin/genetics
- Cholera Toxin/immunology
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Affiliation(s)
- Jae-Deog Kim
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Ah-Ra Lee
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Dah-Hyun Moon
- The Interdisciplinary Graduate Program in Integrative Biotechnology & Translational Medicine, Yonsei University, Incheon, Republic of Korea
| | - Young-Uk Chung
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Su-Yeon Hong
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hyo Je Cho
- Department of Biochemistry, Chungbuk National University, Cheongju, Republic of Korea
| | - Tae Hyun Kang
- Department of Biopharmaceutical Chemistry, Kookmin University, Seoul, Republic of Korea
| | - Yo Han Jang
- Department of Vaccine Biotechnology, Andong National University, Andong, Republic of Korea
| | - Myung Hyun Sohn
- Department of Pediatrics, College of Medicine, Yonsei University, Seoul, Republic of Korea
| | - Baik-Lin Seong
- Department of Microbiology and Immunology, College of Medicine, Yonsei University, Seoul, Republic of Korea
- Vaccine Innovative Technology ALliance (VITAL)-Korea, Yonsei University, Seoul, Republic of Korea
| | - Sang-Uk Seo
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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2
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Lee AR, Kim SH, Hong SY, Lee SH, Oh JS, Lee KY, Kim SJ, Ishikawa T, Shim SM, Lee HI, Seo SU. Characterization of Genotype V Japanese Encephalitis Virus Isolates from Republic of Korea. Emerg Microbes Infect 2024:2362392. [PMID: 38808613 DOI: 10.1080/22221751.2024.2362392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Japanese encephalitis (JE), caused by the Japanese encephalitis virus (JEV) infection, continues to pose significant public health challenges worldwide despite efficient vaccines. The virus is classified into five genotypes, among which genotype V (GV) was not detected for a long period after its initial isolation in 1952, until reports emerged from China and the Republic of Korea (ROK) since 2009. The characteristics of the virus are crucial in estimating its potential epidemiological impact. However, characterization of GV JEVs has so far been limited to two strains: Muar, the original isolate, and XZ0934, isolated in China. Two additional ROK GV JEV isolates, NCCP 43279 and NCCP 43413, are currently available, but their characteristics have not been explored. Our phylogenetic analysis revealed that GV virus sequences from the ROK segregate into two clades. NCCP 43279 and NCCP 43413 belong to different clades and exhibit distinct in vitro phenotypes. NCCP 43279 forms larger plaques but demonstrates inefficient propagation in cell culture compared to NCCP 43413. In vivo, NCCP 43279 induces higher morbidity and mortality in mice than NCCP 43413. Notably, NCCP 43279 shows more severe blood-brain barrier damage, suggesting superior brain invasion capabilities. Consistent with its higher virulence, NCCP 43279 displays more pronounced histopathological and immunopathological outcomes. In conclusion, our study confirms that the two ROK isolates are not only classified into different clades but also exhibit distinct in vitro and in vivo characteristics.
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Affiliation(s)
- Ah-Ra Lee
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sang-Hyun Kim
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Su-Yeon Hong
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sang-Ho Lee
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jae Sang Oh
- Department of Neurosurgery, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Kyung Yong Lee
- Division of Cancer Biology, Research Institute, National Cancer Center, Goyang, Republic of Korea
| | - Seong-Jun Kim
- Center for Infectious Disease Vaccine and Diagnosis Innovation (CEVI), Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea
| | - Tomohiro Ishikawa
- Department of Microbiology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Sang-Mu Shim
- Division of Acute Virus Diseases, Korea National Institute of Health, Korea Disease Control and Prevention Agency, Cheongju, Republic of Korea
| | - Hee Il Lee
- Division of Vectors and Parasitic Diseases, Korea Disease Control and Prevention Agency, Cheongju, Republic of Korea
| | - Sang-Uk Seo
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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3
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Fan YC, Chen JM, Chen YY, Ke YD, Chang GJJ, Chiou SS. Epitope(s) involving amino acids of the fusion loop of Japanese encephalitis virus envelope protein is(are) important to elicit protective immunity. J Virol 2024; 98:e0177323. [PMID: 38530012 PMCID: PMC11019926 DOI: 10.1128/jvi.01773-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 03/06/2024] [Indexed: 03/27/2024] Open
Abstract
Dengue vaccine candidates have been shown to improve vaccine safety and efficacy by altering the residues or accessibility of the fusion loop on the virus envelope protein domain II (DIIFL) in an ex vivo animal study. The current study aimed to comprehensively investigate the impact of DIIFL mutations on the antigenicity, immunogenicity, and protective efficacy of Japanese encephalitis virus (JEV) virus-like particles (VLPs) in mice. We found the DIIFL G106K/L107D (KD) and W101G/G106K/L107D (GKD) mutations altered the binding activity of JEV VLP to cross-reactive monoclonal antibodies but had no effect on their ability to elicit total IgG antibodies in mice. However, JEV VLPs with KD or GKD mutations induced significantly less neutralizing antibodies against JEV. Only 46% and 31% of the KD and GKD VLPs-immunized mice survived compared to 100% of the wild-type (WT) VLP-immunized mice after a lethal JEV challenge. In passive protection experiments, naïve mice that received sera from WT VLP-immunized mice exhibited a significantly higher survival rate of 46.7% compared to those receiving sera from KD VLP- and GKD VLP-immunized mice (6.7% and 0%, respectively). This study demonstrated that JEV DIIFL is crucial for eliciting potently neutralizing antibodies and protective immunity against JEV. IMPORTANCE Introduction of mutations into the fusion loop is one potential strategy for generating safe dengue and Zika vaccines by reducing the risk of severe dengue following subsequent infections, and for constructing live-attenuated vaccine candidates against newly emerging Japanese encephalitis virus (JEV) or Japanese encephalitis (JE) serocomplex virus. The monoclonal antibody studies indicated the fusion loop of JE serocomplex viruses primarily comprised non-neutralizing epitopes. However, the present study demonstrates that the JEV fusion loop plays a critical role in eliciting protective immunity in mice. Modifications to the fusion loop of JE serocomplex viruses might negatively affect vaccine efficacy compared to dengue and zika serocomplex viruses. Further studies are required to assess the impact of mutant fusion loop encoded by commonly used JEV vaccine strains on vaccine efficacy or safety after subsequent dengue virus infection.
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Affiliation(s)
- Yi-Chin Fan
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
- Master of Public Health Degree Program, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Jo-Mei Chen
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ying Chen
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yuan-Dun Ke
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Gwong-Jen J. Chang
- Arboviral Diseases Branch, Centers for Disease Control and Prevention, Fort, Fort Collins, Colorado, USA
| | - Shyan-Song Chiou
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
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4
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Sistrom M, Andrews H, Edwards DL. Comparative genomics of Japanese encephalitis virus shows low rates of recombination and a small subset of codon positions under episodic diversifying selection. PLoS Negl Trop Dis 2024; 18:e0011459. [PMID: 38295106 PMCID: PMC10861042 DOI: 10.1371/journal.pntd.0011459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 02/12/2024] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
Orthoflavivirus japonicum (JEV) is the dominant cause of viral encephalitis in the Asian region with 100,000 cases and 25,000 deaths reported annually. The genome is comprised of a single polyprotein that encodes three structural and seven non-structural proteins. We collated a dataset of 349 complete genomes from a number of public databases, and analysed the data for recombination, evolutionary selection and phylogenetic structure. There are low rates of recombination in JEV, subsequently recombination is not a major evolutionary force shaping JEV. We found a strong overall signal of purifying selection in the genome, which is the main force affecting the evolutionary dynamics in JEV. There are also a small number of genomic sites under episodic diversifying selection, especially in the envelope protein and non-structural proteins 3 and 5. Overall, these results support previous analyses of JEV evolutionary genomics and provide additional insight into the evolutionary processes shaping the distribution and adaptation of this important pathogenic arbovirus.
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Affiliation(s)
- Mark Sistrom
- Department of Industry, Trade and Tourism, Berrimah Veterinary Laboratories, Darwin, Australia
- Research Institute for the Environment and Livelihoods, Faculty of Science and Technology, Charles Darwin University, Casuarina, Australia
| | - Hannah Andrews
- Department of Industry, Trade and Tourism, Berrimah Veterinary Laboratories, Darwin, Australia
| | - Danielle L. Edwards
- Research Institute for the Environment and Livelihoods, Faculty of Science and Technology, Charles Darwin University, Casuarina, Australia
- Department of Natural Sciences, Museum and Art Gallery of the Northern Territory, Darwin, Australia
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5
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Zhang W, Yin Q, Wang H, Liang G. The reemerging and outbreak of genotypes 4 and 5 of Japanese encephalitis virus. Front Cell Infect Microbiol 2023; 13:1292693. [PMID: 38076463 PMCID: PMC10698470 DOI: 10.3389/fcimb.2023.1292693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 10/31/2023] [Indexed: 12/18/2023] Open
Abstract
The Japanese encephalitis virus (JEV) is classified into five distinct genotypes, with genotypes 1 and 3 historically showing higher activity. These genotypes are the primary agents of viral encephalitis in the Asian continent. Genotypes 4 and 5 have remained silent in low-latitude tropical regions since their discovery. From 2009, the hidden genotype 5 suddenly emerged simultaneously in mosquitoes from the Tibetan region of China and those from South Korea in East Asia. The detection of genotype 5 of JEV in these mosquitoes was associated with cases of viral encephalitis in the local population. Similarly, in 2022, the long-silent genotype 4 of JEV emerged in Australia, resulting in a local outbreak of viral encephalitis that primarily affected adults and caused fatalities. The emergence and outbreaks of genotypes 4 and 5 of JEV present new challenges for the prevention and control of Japanese encephalitis (JE). This study not only analyzes the recent emergence of these new genotypes but also discusses their implications in the development of JE vaccines and laboratory tests for newly emerging JEV infections.
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Affiliation(s)
| | | | - Huanyu Wang
- Department of Arbovirus, National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Guodong Liang
- Department of Arbovirus, National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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6
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Zhang X, Jin N, Tu A, Dong M, Shi T, Ren X, Liu S, Zhao X, Liu J, Wu Z, Li Y, Wu D, Wang H, Wang H, Hu Y, Zhang B, Wang W, Meng L. Adults in Northwest China experienced the largest outbreak of Japanese encephalitis in history 10 years after the Japanese encephalitis vaccine was included in the national immunization program: A retrospective epidemiological study. J Med Virol 2023; 95:e28782. [PMID: 37212323 DOI: 10.1002/jmv.28782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/23/2023] [Accepted: 04/28/2023] [Indexed: 05/23/2023]
Abstract
Mainland China included Japanese encephalitis (JE) vaccine in the national immunization program in 2008 to control the JE epidemic. However, Gansu province in Western China experienced the largest JE outbreak since 1958 in 2018. We conducted a retrospective epidemiological study to explore the causes of this outbreak. We found that adults aged ≥20 years (especially those in rural areas) were the main JE cases in Gansu Province, with a significant increase in the JE incidence in older adults aged ≥60 years in 2017 and 2018. In addition, JE outbreaks in Gansu Province were mainly located in the southeastern region, while the temperature and precipitation in Gansu Province were gradually increasing in recent years, which made the JE epidemic areas in Gansu Province gradually spread to the western of Gansu Province. We also found that adults aged ≥20 years in Gansu Province had lower JE antibody positivity than children and infants, and the antibody positivity rate decreased with age. In the summer of 2017 and 2018, the density of mosquitoes (mainly the Culex tritaeniorhynchus) in Gansu Province was significantly higher than in other years, and the genotype of JEV was mainly Genotype-G1. Therefore, in the future JE control in Gansu Province, we need to strengthen JE vaccination for adults. Moreover, strengthening mosquito surveillance can provide early warning of JE outbreaks and the spread of epidemic areas in Gansu Province. At the same time, strengthening JE antibody surveillance is also necessary for JE control.
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Affiliation(s)
- Xiaoshu Zhang
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Na Jin
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Aixia Tu
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Maoxing Dong
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Tianshan Shi
- Institute of Epidemiology and Health Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Xiaowei Ren
- Institute of Epidemiology and Health Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Shuyu Liu
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Xiaohong Zhao
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Jianfeng Liu
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Zhao Wu
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Yixing Li
- Department of Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Dan Wu
- Department of Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Huanyu Wang
- Department of Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Haijun Wang
- Department of Immunization Program, Longnan Center for Disease Control and Prevention, Longnan, China
| | - Yukun Hu
- Department of Immunization Program, Pingliang Center for Disease Control and Prevention, Pingliang, China
| | - Bin Zhang
- Department of Immunization Program, Tianshui Center for Disease Control and Prevention, Tianshui, China
| | - Wenjun Wang
- Department of Immunization Program, Qingyang Center for Disease Control and Prevention, Qingyang, China
| | - Lei Meng
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
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7
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Xu G, Gao T, Wang Z, Zhang J, Cui B, Shen X, Zhou A, Zhang Y, Zhao J, Liu H, Liang G. Re-Emerged Genotype IV of Japanese Encephalitis Virus Is the Youngest Virus in Evolution. Viruses 2023; 15:626. [PMID: 36992335 PMCID: PMC10054483 DOI: 10.3390/v15030626] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/02/2023] Open
Abstract
An outbreak of viral encephalitis caused by a Japanese encephalitis virus (JEV) genotype IV infection occurred in Australia between 2021 and 2022. A total of 47 cases and seven deaths were reported as of November 2022. This is the first outbreak of human viral encephalitis caused by JEV GIV since it was first isolated in Indonesia in the late 1970s. Here, a comprehensive phylogenetic analysis based on the whole genome sequences of JEVs revealed it emerged 1037 years ago (95% HPD: 463 to 2100 years). The evolutionary order of JEV genotypes is as follows: GV, GIII, GII, GI, and GIV. The JEV GIV emerged 122 years ago (95% HPD: 57-233) and is the youngest viral lineage. The mean substitution rate of the JEV GIV lineage was 1.145 × 10-3 (95% HPD values, 9.55 × 10-4, 1.35 × 10-3), belonging to rapidly evolving viruses. A series of amino acid mutations with the changes of physico-chemical properties located in the functional important domains within the core and E proteins distinguished emerging GIV isolates from old ones. These results demonstrate the JEV GIV is the youngest JEV genotype at a rapid evolution stage and has good host/vector adaptability for introduction to non-endemic areas. Thus, surveillance of JEVs is highly recommended.
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Affiliation(s)
- Guanlun Xu
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Tingting Gao
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Zhijie Wang
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Jun Zhang
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Baoqiu Cui
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Xinxin Shen
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Anyang Zhou
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Yuan Zhang
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Jie Zhao
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Hong Liu
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Guangdong Liang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
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8
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Tajima S, Maeki T, Nakayama E, Faizah AN, Kobayashi D, Isawa H, Maekawa Y, Bendryman SS, Mulyatno KC, Rohmah EA, Mori Y, Sawabe K, Ebihara H, Lim CK. Growth, Pathogenesis, and Serological Characteristics of the Japanese Encephalitis Virus Genotype IV Recent Strain 19CxBa-83-Cv. Viruses 2023; 15:239. [PMID: 36680278 PMCID: PMC9866982 DOI: 10.3390/v15010239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 01/19/2023] Open
Abstract
Genotype IV Japanese encephalitis (JE) virus (GIV JEV) is the least common and most neglected genotype in JEV. We evaluated the growth and pathogenic potential of the GIV strain 19CxBa-83-Cv, which was isolated from a mosquito pool in Bali, Indonesia, in 2019, and serological analyses were also conducted. The growth ability of 19CxBa-83-Cv in Vero cells was intermediate between that of the genotype I (GI) strain Mie/41/2002 and the genotype V (GV) strain Muar, whereas 19CxBa-83-Cv and Mie/41/2002 grew faster than Muar in mouse neuroblastoma cells. The neuroinvasiveness of 19CxBa-83-Cv in mice was higher than that of Mie/41/2002 but lower than that of Muar; however, there were no significant differences in neurovirulence in mice among the three strains. The neutralizing titers of sera from 19CxBa-83-Cv- and Mie/41/2002-inoculated mice against 19CxBa-83-Cv and Mie/41/2002 were similar, whereas the titers against Muar were lower than those of the other two viruses. The neutralizing titers of JE vaccine-inoculated mouse pool serum against 19CxBa-83-Cv and Muar were significantly lower than those against Mie/41/2002. The neutralizing titers against the three viruses were similar in three out of the five serum samples from GI-infected JE patients, although the titers against Mie/41/2002 were higher than those against 19CxBa-83-Cv and Muar in the remaining two sera samples. In summary, we identified the basic characteristics of 19CxBa-83-Cv, but further studies are needed to better understand GIV JEV.
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Affiliation(s)
- Shigeru Tajima
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Takahiro Maeki
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Eri Nakayama
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Astri Nur Faizah
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Daisuke Kobayashi
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Haruhiko Isawa
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Yoshihide Maekawa
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Sri Subekti Bendryman
- Laboratory of Entomology, Institute of Tropical Diseases, Universitas Airlangga, Surabaya 60115, Indonesia
| | - Kris Cahyo Mulyatno
- Laboratory of Entomology, Institute of Tropical Diseases, Universitas Airlangga, Surabaya 60115, Indonesia
| | - Etik Ainun Rohmah
- Laboratory of Entomology, Institute of Tropical Diseases, Universitas Airlangga, Surabaya 60115, Indonesia
| | - Yasuko Mori
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Kyoko Sawabe
- Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Hideki Ebihara
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Chang-Kweng Lim
- Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
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9
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Crispell G, Williams K, Zielinski E, Iwami A, Homas Z, Thomas K. Method comparison for Japanese encephalitis virus detection in samples collected from the Indo-Pacific region. Front Public Health 2022; 10:1051754. [PMID: 36504937 PMCID: PMC9730272 DOI: 10.3389/fpubh.2022.1051754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction Japanese encephalitis virus (JEV) is a mosquito-borne viral pathogen, which is becoming a growing public health concern throughout the Indo-Pacific. Five genotypes of JEV have been identified. Current vaccines are based on genotype III and provide a high degree of protection for four of the five known genotypes. Methods RT-PCR, Magpix, Twist Biosciences Comprehensive Viral Research Panel (CVRP), and SISPA methods were used to detect JEV from mosquito samples collected in South Korea during 2021. These methods were compared to determine which method would be most effective for biosurveillance in the Indo-Pacific region. Results Our data showed that RT-PCR, Twist CVRP, and SISPA methods were all able to detect JEV genotype I, however, the proprietary Magpix panel was only able to detect JEV genotype III. Use of minION sequencing for pathogen detection in arthropod samples will require further method development. Conclusion Biosurveillance of vectorborne pathogens remains an area of concern throughout the Indo-Pacific. RT-PCR was the most cost effective method used in the study, but TWIST CVRP allows for the identification of over 3,100 viral genomes. Further research and comparisons will be conducted to ensure optimal methods are used for large scale biosurveillance.
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Japanese Encephalitis Virus: The Emergence of Genotype IV in Australia and Its Potential Endemicity. Viruses 2022; 14:v14112480. [PMID: 36366578 PMCID: PMC9698845 DOI: 10.3390/v14112480] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
A fatal case of Japanese encephalitis (JE) occurred in northern Australia in early 2021. Sequence studies showed that the virus belonged to genotype IV (GIV), a genotype previously believed to be restricted to the Indonesian archipelago. This was the first locally acquired case of Japanese encephalitis virus (JEV) GIV to occur outside Indonesia, and the second confirmed fatal human case caused by a GIV virus. A closely related GIV JEV strain subsequently caused a widespread outbreak in eastern Australia in 2022 that was first detected by fetal death and abnormalities in commercial piggeries. Forty-two human cases also occurred with seven fatalities. This has been the first major outbreak of JEV in mainland Australia, and geographically the largest virgin soil outbreak recorded for JEV. This outbreak provides an opportunity to discuss and document the factors involved in the virus' spread and its ecology in a novel ecological milieu in which other flaviviruses, including members of the JE serological complex, also occur. The probable vertebrate hosts and mosquito vectors are discussed with respect to virus spread and its possible endemicity in Australia, and the need to develop a One Health approach to develop improved surveillance methods to rapidly detect future outbreak activity across a large geographical area containing a sparse human population. Understanding the spread of JEV in a novel ecological environment is relevant to the possible threat that JEV may pose in the future to other receptive geographic areas, such as the west coast of the United States, southern Europe or Africa.
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11
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Khare B, Kuhn RJ. The Japanese Encephalitis Antigenic Complex Viruses: From Structure to Immunity. Viruses 2022; 14:2213. [PMID: 36298768 PMCID: PMC9607441 DOI: 10.3390/v14102213] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 11/09/2022] Open
Abstract
In the last three decades, several flaviviruses of concern that belong to different antigenic groups have expanded geographically. This has resulted in the presence of often more than one virus from a single antigenic group in some areas, while in Europe, Africa and Australia, additionally, multiple viruses belonging to the Japanese encephalitis (JE) serogroup co-circulate. Morphological heterogeneity of flaviviruses dictates antibody recognition and affects virus neutralization, which influences infection control. The latter is further impacted by sequential infections involving diverse flaviviruses co-circulating within a region and their cross-reactivity. The ensuing complex molecular virus-host interplay leads to either cross-protection or disease enhancement; however, the molecular determinants and mechanisms driving these outcomes are unclear. In this review, we provide an overview of the epidemiology of four JE serocomplex viruses, parameters affecting flaviviral heterogeneity and antibody recognition, host immune responses and the current knowledge of the cross-reactivity involving JE serocomplex flaviviruses that leads to differential clinical outcomes, which may inform future preventative and therapeutic interventions.
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Affiliation(s)
- Baldeep Khare
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Richard J. Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
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12
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Effectiveness of Live-Attenuated Genotype III Japanese Encephalitis Viral Vaccine against Circulating Genotype I Viruses in Swine. Viruses 2022; 14:v14010114. [PMID: 35062317 PMCID: PMC8778556 DOI: 10.3390/v14010114] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/02/2022] [Accepted: 01/07/2022] [Indexed: 01/15/2023] Open
Abstract
Expansion of genotype I (GI) Japanese encephalitis viruses (JEV) has resulted in the replacement of the dominant genotype III (GIII) viruses, raising serious public health concerns for using GIII virus-derived vaccines to effectively control JEV epidemics. Therefore, this study used swine as the model to estimate the effectiveness of GIII live-attenuated vaccine against GI virus infection by comparing the incidence of stillbirth/abortion in gilts from vaccinated and non-vaccinated pig farms during the GI-circulation period. In total, 389 and 213 litters of gilts were recorded from four vaccinated and two non-vaccinated pig farms, respectively. All viruses detected in the aborted fetuses and mosquitoes belonged to the GI genotype during the study period. We thus estimated that the vaccine effectiveness of GIII live-attenuated vaccine against GI viruses in naive gilts based on the overall incidence of stillbirth/abortion and incidence of JEV-confirmed stillbirth/abortion was 65.5% (50.8–75.7%) and 74.7% (34.5–90.2%), respectively. In contrast to previous estimates, the GIII live-attenuated vaccine had an efficacy of 95.6% (68.3–99.4%) to prevent the incidence of stillbirth/abortion during the GIII-circulating period. These results indicate that the vaccine effectiveness of GIII live-attenuated JEV vaccine to prevent stillbirth/abortion caused by GI viruses is lower than that against GIII viruses.
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13
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Chiou SS, Chen JM, Chen YY, Chia MY, Fan YC. The feasibility of field collected pig oronasal secretions as specimens for the virologic surveillance of Japanese encephalitis virus. PLoS Negl Trop Dis 2021; 15:e0009977. [PMID: 34860839 PMCID: PMC8673640 DOI: 10.1371/journal.pntd.0009977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/15/2021] [Accepted: 11/05/2021] [Indexed: 11/24/2022] Open
Abstract
Virologic surveillance of Japanese encephalitis virus (JEV) relies on collecting pig blood specimens and adult mosquitoes in the past. Viral RNAs extracted from pig blood specimens suffer from low detecting positivity by reverse transcription PCR (RT-PCR). The oronasal transmission of the virus has been demonstrated in experimentally infected pigs. This observation suggested oronasal specimens could be useful source in the virus surveillance. However, the role of this unusual route of transmission remains unproven in the operational pig farm. In this study, we explore the feasibility of using pig oronasal secretions collected by chewing ropes to improve the positivity of detection in commercial pig farms. The multiplex genotype-specific RT-PCR was used in this study to determine and compare the positivity of detecting JEV viral RNAs in pig’s oronasal secretions and blood specimens, and the primary mosquito vector. Oronasal specimens had the overall positive rate of 6.0% (95% CI 1.3%–16.6%) (3/50) to 10.0% (95% CI 2.1%–26.5%) (3/30) for JEV during transmission period despite the negative results of all blood-derived specimens (n = 2442). Interestingly, pig oronasal secretions and female Culex tritaeniorhynchus mosquito samples collected from the same pig farm showed similar viral RNA positive rates, 10.0% (95% CI 2.1%–26.5%) (3/30) and 8.9% (95% CI 2.5%–21.2%) (4/45), respectively (p> 0.05). Pig oronasal secretion-based surveillance revealed the seasonality of viral activity and identified closely related genotype I virus derived from the mosquito isolates. This finding indicates oronasal secretion-based RT-PCR assay can be a non-invasive, alternative method of implementing JEV surveillance in the epidemic area prior to the circulation of virus-positive mosquitoes. Mosquito-borne Japanese encephalitis virus (JEV) has either endemic or seasonal patterns of transmission in Asia and Australia. Most hosts infected by the virus remains asymptomatic but can result in severe encephalitis in humans and horses, and abortion or stillbirth in pregnant sows. Isolation of virus in adult mosquitoes or pig seroconversion has been used as an early indicator of upcoming JE outbreak in humans. Genotype identification of the virus is important since current human and domestic animal vaccines are all genotype III (GIII) specific. GIII vaccine elicited immunity has reduced cross-protections to genotypes other than GIII. Our virologic surveillance using pig’s oronasal secretion detected higher prevalence and earlier genotype I virus activity than using pig’s blood and mosquitoes, respectively. This proposed surveillance tool might be more effective that will allow the public health agency to properly implement the preventive measures, such as implementing mosquito control, encouraging booster vaccination, and encouraging the use of mosquito repellent, to reduce the impact of upcoming outbreak. Collection of pig’s oronasal secretion is non-invasive to pigs and less technically demanding to operators. Thus we propose the use of pig’s oronasal secretions as the novel source of specimens for virologic surveillance to replace the traditional pig blood or adult mosquito specimens to monitor and control JE outbreak/epidemic in the future.
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Affiliation(s)
- Shyan-Song Chiou
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Jo-Mei Chen
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ying Chen
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Min-Yuan Chia
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Chin Fan
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
- * E-mail:
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Mulvey P, Duong V, Boyer S, Burgess G, Williams DT, Dussart P, Horwood PF. The Ecology and Evolution of Japanese Encephalitis Virus. Pathogens 2021; 10:1534. [PMID: 34959489 PMCID: PMC8704921 DOI: 10.3390/pathogens10121534] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus mainly spread by Culex mosquitoes that currently has a geographic distribution across most of Southeast Asia and the Western Pacific. Infection with JEV can cause Japanese encephalitis (JE), a severe disease with a high mortality rate, which also results in ongoing sequalae in many survivors. The natural reservoir of JEV is ardeid wading birds, such as egrets and herons, but pigs commonly play an important role as an amplifying host during outbreaks in human populations. Other domestic animals and wildlife have been detected as hosts for JEV, but their role in the ecology and epidemiology of JEV is uncertain. Safe and effective JEV vaccines are available, but unfortunately, their use remains low in most endemic countries where they are most needed. Increased surveillance and diagnosis of JE is required as climate change and social disruption are likely to facilitate further geographical expansion of Culex vectors and JE risk areas.
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Affiliation(s)
- Peter Mulvey
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia;
| | - Veasna Duong
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Sebastien Boyer
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Graham Burgess
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia;
| | - David T. Williams
- Australian Centre for Disease Preparedness, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Geelong 3220, Australia;
| | - Philippe Dussart
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Paul F. Horwood
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia;
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia;
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15
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Abstract
Japanese encephalitis (JE) is an endemic disease dominantly in the Asia-Pacific region with mortality rate varying between 3% and 30%. Long-term neuropsychiatric sequelae developed in 30–50% of the survivors. There is no available antiviral therapy for JE. JE vaccines play a major role in preventing this devastating disease. The incidence of JE declined over years and the age distribution shifted toward adults in countries where JE immunization program exists. Mouse brain–JE vaccine is currently replaced by inactivated Vero cell-derived vaccine and live-attenuated vaccine using SA14-14-2 strain, and live chimeric JE vaccines. These three types of JE vaccines are associated with favorable efficacy and safety profiles. Common adverse reactions include injection site reactions and fever, and severe adverse reactions are rare.
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Affiliation(s)
- Ya-Li Hu
- Department of Pediatrics, Cathay General Hospital, Taipei, Taiwan
| | - Ping-Ing Lee
- Department of Pediatrics, National Taiwan University Hospital, and National Taiwan University College of Medicine, Taipei, Taiwan
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16
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Japanese encephalitis virus live attenuated vaccine strains display altered immunogenicity, virulence and genetic diversity. NPJ Vaccines 2021; 6:112. [PMID: 34475404 PMCID: PMC8413339 DOI: 10.1038/s41541-021-00371-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 06/16/2021] [Indexed: 02/07/2023] Open
Abstract
Japanese encephalitis virus (JEV) is the etiological agent of Japanese encephalitis (JE). The most commonly used vaccine used to prevent JE is the live-attenuated strain SA14-14-2, which was generated by serial passage of the wild-type (WT) JEV strain SA14. Two other vaccine candidates, SA14-5-3 and SA14-2-8 were derived from SA14. Both were shown to be attenuated but lacked sufficient immunogenicity to be considered effective vaccines. To better contrast the SA14-14-2 vaccine with its less-immunogenic counterparts, genetic diversity, ribavirin sensitivity, mouse virulence and mouse immunogenicity of the three vaccines were investigated. Next generation sequencing demonstrated that SA14-14-2 was significantly more diverse than both SA14-5-3 and SA14-2-8, and was slightly less diverse than WT SA14. Notably, WT SA14 had unpredictable levels of diversity across its genome whereas SA14-14-2 is highly diverse, but genetic diversity is not random, rather the virus only tolerates variability at certain residues. Using Ribavirin sensitivity in vitro, it was found that SA14-14-2 has a lower fidelity replication complex compared to SA14-5-3 and SA14-2-8. Mouse virulence studies showed that SA14-2-8 was the most virulent of the three vaccine strains while SA14-14-2 had the most favorable combination of safety (virulence) and immunogenicity for all vaccines tested. SA14-14-2 contains genetic diversity and sensitivity to the antiviral Ribavirin similar to WT parent SA14, and this genetic diversity likely explains the (1) differences in genomic sequences reported for SA14-14-2 and (2) the encoding of major attenuation determinants by the viral E protein.
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17
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Khan SA, Choudhury P, Kakati S, Doley R, Barman MP, Murhekar MV, Kaur H. Effectiveness of a single dose of Japanese encephalitis vaccine among adults, Assam, India, 2012-2018. Vaccine 2021; 39:4973-4978. [PMID: 34325931 DOI: 10.1016/j.vaccine.2021.07.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 05/24/2021] [Accepted: 07/16/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Japanese encephalitis virus (JEV) remains the major etiology of encephalitis throughout Asia. In India, the state of Assam alone contributes more than one-third of the national burden of JE. Between 2011 and 2014, a single dose of JE vaccine SA 14-14-2 (LAJEV) was administered among adults aged 15-65 years residing in Sivasagar and Dibrugarh districts of Assam, India. We monitored the trend of JE incidence between 2009 and 2018 using JE surveillance data, estimated the long-term effectiveness of the single dose of LAJEV and estimated the coverage of JE vaccine in two districts. METHODS We compared the JE vaccination status of laboratory-confirmed hospitalized JE patients (case) and age, sex and locality matched healthy individuals (controls) to estimate the effectiveness of single dose of JE vaccine. We used surveillance data for 2009-2018 to calculate the incidence of JE among adults. We conducted a community-based survey to estimate the coverage of JE vaccine in the two districts. RESULTS A total of 452 laboratory-confirmed JE case-patients and 904 matched healthy controls were enrolled in the study between 2012 and 2018. The effectiveness of a single dose of JE vaccine over the 7-year period was 77.0 (95% CI: 67.0-83.0). Vaccine effectiveness decreased from 91% (95% CI: 73.0-97.0) in first year of vaccination to 71% (95% CI: 21.0-90.0) at six years post-vaccination. The incidence of adults JE cases declined from 10.5 per 100,000 in the pre-vaccination period to 5.7 per 100,000 in the years following vaccination. The coverage of vaccine among adults in two districts was 40.1% (36.8-43.5). CONCLUSIONS A single dose of JE vaccine offered adequate protection for at least six years. Conducting mass vaccination campaigns periodically would further reduce the incidence of JE in endemic districts in Assam.
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Affiliation(s)
- Siraj A Khan
- Department of Medical Entomology, Arbovirology and Rickettsial Diseases, Indian Council of Medical Research-Regional Medical Research Centre, Dibrugarh, Assam, India.
| | - Parveena Choudhury
- Department of Medical Entomology, Arbovirology and Rickettsial Diseases, Indian Council of Medical Research-Regional Medical Research Centre, Dibrugarh, Assam, India
| | - Sanjeeb Kakati
- Assam Medical College and Hospital, Dibrugarh, Assam, India
| | - Rimamoni Doley
- Assam Medical College and Hospital, Dibrugarh, Assam, India
| | - Manash P Barman
- Department of Statistics, Dibrugarh University, Dibrugarh, Assam, India
| | - Manoj V Murhekar
- Indian Council of Medical Research-National Institute of Epidemiology, Chennai, Tamil Nadu, India
| | - Harpreet Kaur
- Indian Council of Medical Research, New Delhi, India
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18
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Vannice KS, Hills SL, Schwartz LM, Barrett AD, Heffelfinger J, Hombach J, Letson GW, Solomon T, Marfin AA. The future of Japanese encephalitis vaccination: expert recommendations for achieving and maintaining optimal JE control. NPJ Vaccines 2021; 6:82. [PMID: 34131150 PMCID: PMC8206071 DOI: 10.1038/s41541-021-00338-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 04/15/2021] [Indexed: 02/05/2023] Open
Abstract
Vaccines against Japanese encephalitis (JE) have been available for decades. Currently, most JE-endemic countries have vaccination programs for their at-risk populations. Even so, JE remains the leading recognized cause of viral encephalitis in Asia. In 2018, the U.S. Centers for Disease Control and Prevention and PATH co-convened a group of independent experts to review JE prevention and control successes, identify remaining scientific and operational issues that need to be addressed, discuss opportunities to further strengthen JE vaccination programs, and identify strategies and solutions to ensure sustainability of JE control during the next decade. This paper summarizes the key discussion points and recommendations to sustain and expand JE control.
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Affiliation(s)
| | - Susan L Hills
- Arboviral Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, CO, USA
| | | | - Alan D Barrett
- Sealy Institute for Vaccine Sciences, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | | | - Joachim Hombach
- Department of Immunizations, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | | | - Tom Solomon
- National Institute for Health Research Health Protection Research Unit in Emerging and Zoonotic Infections, and Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
- Walton Centre NHS Foundation Trust, Liverpool, UK
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19
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Dey D, Poudyal S, Rehman A, Hasan SS. Structural and biochemical insights into flavivirus proteins. Virus Res 2021; 296:198343. [PMID: 33607183 DOI: 10.1016/j.virusres.2021.198343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 01/01/2023]
Abstract
Flaviviruses are the fastest spreading arthropod-borne viruses that cause severe symptoms such as hepatitis, hemorrhagic fever, encephalitis, and congenital deformities. Nearly 40 % of the entire human population is at risk of flavivirus epidemics. Yet, effective vaccination is restricted only to a few flaviviruses such as yellow fever and Japanese encephalitis viruses, and most recently for select cases of dengue virus infections. Despite the global spread of dengue virus, and emergence of new threats such as Zika virus and a new genotype of Japanese encephalitis virus, insights into flavivirus targets for potentially broad-spectrum vaccination are limited. In this review article, we highlight biochemical and structural differences in flavivirus proteins critical for virus assembly and host interactions. A comparative sequence analysis of pH-responsive properties of viral structural proteins identifies trends in conservation of complementary acidic-basic character between interacting viral structural proteins. This is highly relevant to the understanding of pH-sensitive differences in virus assembly in organelles such as neutral ER and acidic Golgi. Surface residues in viral interfaces identified by structural approaches are shown to demonstrate partial conservation, further reinforcing virus-specificity in assembly and interactions with host proteins. A comparative analysis of epitope conservation in emerging flaviviruses identifies therapeutic antibody candidates that have potential as broad spectrum anti-virals, thus providing a path towards development of vaccines.
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Affiliation(s)
- Debajit Dey
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore MD 21201, USA
| | - Shishir Poudyal
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette IN 47907, USA
| | - Asma Rehman
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore MD 21201, USA
| | - S Saif Hasan
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore MD 21201, USA; University of Maryland Marlene and Stewart Greenebaum Cancer Center, University of Maryland Medical Center, 22. S. Greene St. Baltimore MD 21201, USA; Center for Biomolecular Therapeutics, University of Maryland School of Medicine, 9600 Gudelsky Drive, Rockville MD 20850, USA.
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20
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Kim HH, Yang DK, Ji M, Lee SK, Hyun BH. Genotype-specific neutralizing antibody titers against Japanese encephalitis virus genotypes 1 and 3 in horses immunized with a genotype 3 vaccine. Clin Exp Vaccine Res 2020; 9:102-107. [PMID: 32864366 PMCID: PMC7445317 DOI: 10.7774/cevr.2020.9.2.102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/25/2020] [Accepted: 07/28/2020] [Indexed: 11/15/2022] Open
Abstract
Purpose Japanese encephalitis is one of the most important mosquito-borne and zoonotic diseases in Asia and the Pacific region. Although the dominant Japanese encephalitis virus (JEV) genotype has shifted from G3 to G1 in Korea since 1990, a G3 strain (Anyang 300) has been used in vaccines for horses for almost 40 years. This study aimed to investigate the seroconversion rates and geometric mean titers (GMTs) of virus-neutralizing antibodies (VNAs) against JEV G1 and G3 in horses immunized with the G3 vaccine. Materials and Methods Serum samples of 1,231 horses immunized with the Anyang 300 vaccine were collected in 2018. VNA titers against JEV KV1899 (G1) and Anyang 300 (G3) were measured in all serum samples using the virus neutralization test. Titers were analyzed according to blood sampling time (prior to and following annual revaccination), age, and region. Results Rates of VNA titer >10 were 45.1% and 77.8% for G1, and 49.1% and 82.9% for G3 in samples taken before and after revaccination, respectively. GMTs of genotype-specific VNAs against JEV G1 and G3 were 8.3 and 11.6 before revaccination and rose to 27.2 and 65.4 following revaccination. Overall sero-positivity did not significantly differ between genotypes, but GMTs significantly differed among genotypes and sampling times. No significant difference was found in GMTs among age groups or regions. Conclusion Genotype-specific neutralizing antibody titers against JEV G1 and G3 differed significantly in horses immunized with the G3 vaccine. Antigenic differences between genotypes could reduce the vaccine's efficacy, requiring the development of a new vaccine.
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Affiliation(s)
- Ha-Hyun Kim
- Viral Disease Research Division, Animal and Plant Quarantine Agency, Gimcheon, Korea
| | - Dong-Kun Yang
- Viral Disease Research Division, Animal and Plant Quarantine Agency, Gimcheon, Korea
| | - Miryeon Ji
- Viral Disease Research Division, Animal and Plant Quarantine Agency, Gimcheon, Korea
| | | | - Bang-Hun Hyun
- Viral Disease Research Division, Animal and Plant Quarantine Agency, Gimcheon, Korea
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21
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Araujo SC, Pereira LR, Alves RPS, Andreata-Santos R, Kanno AI, Ferreira LCS, Gonçalves VM. Anti-Flavivirus Vaccines: Review of the Present Situation and Perspectives of Subunit Vaccines Produced in Escherichia coli. Vaccines (Basel) 2020; 8:vaccines8030492. [PMID: 32878023 PMCID: PMC7564369 DOI: 10.3390/vaccines8030492] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/22/2020] [Accepted: 08/23/2020] [Indexed: 12/14/2022] Open
Abstract
This article aims to review the present status of anti-flavivirus subunit vaccines, both those at the experimental stage and those already available for clinical use. Aspects regarding development of vaccines to Yellow Fever virus, (YFV), Dengue virus (DENV), West Nile virus (WNV), Zika virus (ZIKV), and Japanese encephalitis virus (JEV) are highlighted, with particular emphasis on purified recombinant proteins generated in bacterial cells. Currently licensed anti-flavivirus vaccines are based on inactivated, attenuated, or virus-vector vaccines. However, technological advances in the generation of recombinant antigens with preserved structural and immunological determinants reveal new possibilities for the development of recombinant protein-based vaccine formulations for clinical testing. Furthermore, novel proposals for multi-epitope vaccines and the discovery of new adjuvants and delivery systems that enhance and/or modulate immune responses can pave the way for the development of successful subunit vaccines. Nonetheless, advances in this field require high investments that will probably not raise interest from private pharmaceutical companies and, therefore, will require support by international philanthropic organizations and governments of the countries more severely stricken by these viruses.
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Affiliation(s)
- Sergio C. Araujo
- Laboratory of Vaccine Development, Instituto Butantan, São Paulo–SP 05503-900, Brazil; (S.C.A.); (A.I.K.)
| | - Lennon R. Pereira
- Laboratory of Vaccine Development, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo–SP 05508-000, Brazil; (L.R.P.); (R.P.S.A.); (R.A.-S.)
| | - Rubens P. S. Alves
- Laboratory of Vaccine Development, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo–SP 05508-000, Brazil; (L.R.P.); (R.P.S.A.); (R.A.-S.)
| | - Robert Andreata-Santos
- Laboratory of Vaccine Development, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo–SP 05508-000, Brazil; (L.R.P.); (R.P.S.A.); (R.A.-S.)
| | - Alex I. Kanno
- Laboratory of Vaccine Development, Instituto Butantan, São Paulo–SP 05503-900, Brazil; (S.C.A.); (A.I.K.)
| | - Luis Carlos S. Ferreira
- Laboratory of Vaccine Development, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo–SP 05508-000, Brazil; (L.R.P.); (R.P.S.A.); (R.A.-S.)
- Correspondence: (L.C.S.F.); (V.M.G.)
| | - Viviane M. Gonçalves
- Laboratory of Vaccine Development, Instituto Butantan, São Paulo–SP 05503-900, Brazil; (S.C.A.); (A.I.K.)
- Correspondence: (L.C.S.F.); (V.M.G.)
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Kling K, Harder T, Younger Z, Burchard G, Schmidt-Chanasit J, Wichmann O. Vaccination against Japanese encephalitis with IC51: systematic review on immunogenicity, duration of protection and safety. J Travel Med 2020; 27:5732465. [PMID: 32043122 DOI: 10.1093/jtm/taaa016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/28/2020] [Indexed: 01/04/2023]
Abstract
Japanese encephalitis is a disease caused by a flavivirus which is transmitted by mosquitos in endemic countries. Considering the potentially severe outcomes of the disease, vaccination is recommended for those at risk of exposure. During recent years, IC51 (IXIARO®, JESPECT®, JEVAL®) has increasingly been used to protect travellers from Europe and the USA. However, no systematic review exists that summarizes the currently available evidence on the immunogenicity and safety of this vaccine. We conducted a systematic review on the immunogenicity and safety of IC51, using the databases PubMed, MEDLINE, EMBASE and ClinicalTrials.gov (search date: 31 August 2019). Data extracted from included studies were grouped by outcomes and stratified by population and setting. Risk of bias (ROB) was assessed using the RoB 2 tool for randomized controlled trials (RCTs) and ROBINS-I for non-randomized studies. Due to high heterogeneity, meta-analysis was not performed. A total of 32 studies from 16 countries met the inclusion criteria (15 RCTs, 17 non-randomized studies). ROB was serious or high in the majority of studies. Seroprotection rates ranged from 93 to 100% in adults (seven studies) and from 91 to 100% in children (four studies). In the study involving adults aged 64 years and older, seroprotection was 65% with higher rates in persons who were previously vaccinated against tick-borne encephalitis virus. Safety was investigated in 27 studies. Rates of serious adverse events were below 5% in all age groups, with the majority not being causally related to the vaccine. IC51 is a safe vaccine with good seroprotective abilities in persons aged >2 months to <64 years. The body of evidence, however, is weakened by a large amount of heterogeneity in study and clinical trial methodology. Further well-designed RCTs with special risk groups are needed.
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Affiliation(s)
- Kerstin Kling
- Immunization Unit, Robert Koch Institute, Berlin 13353, Germany
| | - Thomas Harder
- Immunization Unit, Robert Koch Institute, Berlin 13353, Germany
| | - Zane Younger
- Immunization Unit, Robert Koch Institute, Berlin 13353, Germany
| | - Gerd Burchard
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg 20359, Germany
| | - Jonas Schmidt-Chanasit
- Bernhard-Nocht-Institute for Tropical Medicine, Hamburg 20359, Germany
- Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Hamburg 22609, Germany
| | - Ole Wichmann
- Immunization Unit, Robert Koch Institute, Berlin 13353, Germany
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Lee PI, Huang YC, Hwang KP, Liu CC, Chiu CH, Chen PY, Lu CY, Chen CJ, Chang LY, Chiu NC, Chi H, Lin HC, Wu KG, Ho YH, Sun W, Lin TY. Recommendations for the use of Japanese encephalitis vaccines. Pediatr Neonatol 2020; 61:3-8. [PMID: 31870559 DOI: 10.1016/j.pedneo.2019.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 06/03/2019] [Accepted: 11/21/2019] [Indexed: 12/28/2022] Open
Abstract
Japanese encephalitis (JE) is a mosquito-borne viral infection which is prevalent in Taiwan. The virus circulates in an enzootic cycle in pigs which serve as amplifying hosts. Outbreaks typically occur during summer. A universal vaccination program using 4-shot mouse brain-derived inactivated vaccine has successfully controlled JE epidemics in Taiwan since 1968. More than 90% of JE cases in recent years were older than 20 years in Taiwan. Because of several drawbacks, mouse brain-derived vaccine has been replaced by newer generation JE vaccines, including inactivated Vero cell-derived vaccine and live chimeric vaccine. The present article describes the recommendations in Taiwan for the use of new JE vaccines and the schedules for shifting between different JE vaccines.
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Affiliation(s)
- Ping-Ing Lee
- Department of Pediatrics, National Taiwan University Children's Hospital, National Taiwan University Hospital and National Taiwan University College of Medicine, National Taiwan University, Taiwan.
| | - Yhu-Chering Huang
- Division of Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taiwan
| | - Kao-Pin Hwang
- School of Medicine, China Medical University; Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, Taiwan
| | - Ching-Chuan Liu
- Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Taiwan
| | - Cheng-Hsun Chiu
- Division of Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taiwan
| | - Po-Yen Chen
- Section of Pediatric Infectious Diseases, Department of Pediatrics, Taichung Veterans General Hospital, Taiwan
| | - Chun-Yi Lu
- Department of Pediatrics, National Taiwan University Children's Hospital, National Taiwan University Hospital and National Taiwan University College of Medicine, National Taiwan University, Taiwan
| | - Chih-Jung Chen
- Division of Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taiwan
| | - Luan-Yin Chang
- Department of Pediatrics, National Taiwan University Children's Hospital, National Taiwan University Hospital and National Taiwan University College of Medicine, National Taiwan University, Taiwan
| | - Nan-Chang Chiu
- Department of Pediatrics, MacKay Children's Hospital, Taiwan
| | - Hsin Chi
- Department of Pediatrics, MacKay Children's Hospital, Taiwan
| | - Hsiao-Chuan Lin
- School of Medicine, China Medical University; Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, Taiwan
| | - Keh-Gong Wu
- Department of Pediatrics, Taipei Veterans General Hospital and National Yang-Ming University, Taiwan
| | - Yu-Huai Ho
- Division of Infection Diseases, Department of Internal Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Taiwan
| | - Wu Sun
- Pao-Chien Hospital, Taiwan
| | - Tzou-Yien Lin
- Division of Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taiwan
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24
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Young CL, Lyons AC, Hsu WW, Vanlandingham DL, Park SL, Bilyeu AN, Ayers VB, Hettenbach SM, Zelenka AM, Cool KR, Peterson GJ, Higgs S, Huang YJS. Protection of swine by potent neutralizing anti-Japanese encephalitis virus monoclonal antibodies derived from vaccination. Antiviral Res 2019; 174:104675. [PMID: 31825852 DOI: 10.1016/j.antiviral.2019.104675] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/03/2019] [Accepted: 12/06/2019] [Indexed: 12/31/2022]
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus endemic in the Asia Pacific region. Despite use of several highly effective vaccines, it is estimated that up to 44,000 new cases of Japanese encephalitis (JE) occur every year including 14,000 deaths and 24,000 survivors with permanent sequelae. Humoral immunity induced by vaccination is critical for effective protection. Potently neutralizing antibodies reactive with the JEV envelope (E) protein are important since protective immune responses induced by both live-attenuated and inactivated JE vaccines target the E protein. Our understanding of how vaccine-induced humoral immunity protects vaccinees from morbidity and mortality is, however, limited and largely obtained from in vitro studies. With the exception of neurovirulence mouse models, very few platforms are available for evaluating the protective efficacy of neutralizing antibodies against JEV in vivo. Swine are a major amplifying host in the natural JEV transmission cycle and develop multiple pathological outcomes similar to humans infected with JEV. In this study, prophylactic passive immunization was performed in a miniature swine model, using two vaccination-induced monoclonal antibodies (mAb), JEV-31 and JEV-169. These were selected as representatives for antibodies reactive with the major antigenic structures in the E protein of JEV and related flaviviruses. JEV-31 recognizes the lateral ridge of E protein domain III (EDIII) whilst JEV-169 has a broad footprint of binding involving residues throughout domains I (EDI) and II (EDII) of the E protein. Detection of neutralizing antibodies in the serum of immunized animals mimics the presence of neutralizing antibodies in vaccinated individuals. Passive immunization with both mAbs significantly reduced the severity of diseases that resemble the symptoms of human JE including fever, viremia, viral shedding, systemic infection, and neuroinvasion. In contrast to the uniformed decrease of viral loads in lymphoid and central nervous systems, distinct kinetics in the onset of fever and viremia between animals receiving JEV-31 and JEV-169 suggest potential differences in immune protection mechanisms between anti-EDI and anti-EDIII neutralizing antibodies elicited by vaccination. Our data demonstrate the feasibility of using swine models in characterizing the protective humoral immunity against JEV and increase our understanding of how clonal populations of anti-E mAbs derived from JE vaccination protect against infection in vivo.
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Affiliation(s)
- Christian L Young
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA; National Bio- and Agro-Defense Facility Scientist Training Program, Animal and Plant Health Inspection Service, United States Department of Agriculture, USA
| | - Amy C Lyons
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA
| | - Wei-Wen Hsu
- Department of Statistics, College of Arts and Sciences, Kansas State University, Manhattan, KS, USA
| | - Dana L Vanlandingham
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA
| | - So Lee Park
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA
| | - Ashley N Bilyeu
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA
| | - Victoria B Ayers
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA; National Bio- and Agro-Defense Facility Scientist Training Program, Animal and Plant Health Inspection Service, United States Department of Agriculture, USA
| | - Susan M Hettenbach
- Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA
| | - Ashley M Zelenka
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA
| | - Konner R Cool
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA
| | - Gregory J Peterson
- University Research Compliance Office, Kansas State University, Manhattan, KS, USA
| | - Stephen Higgs
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA
| | - Yan-Jang S Huang
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Biosecurity Research Institute, Kansas State University, Manhattan, KS, USA.
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Virus-Like Particle Systems for Vaccine Development against Viruses in the Flaviviridae Family. Vaccines (Basel) 2019; 7:vaccines7040123. [PMID: 31547131 PMCID: PMC6963367 DOI: 10.3390/vaccines7040123] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/07/2019] [Accepted: 09/13/2019] [Indexed: 01/07/2023] Open
Abstract
Viruses in the Flaviviridae family are important human and animal pathogens that impose serious threats to global public health. This family of viruses includes emerging and re-emerging viruses, most of which are transmitted by infected mosquito or tick bites. Currently, there is no protective vaccine or effective antiviral treatment against the majority of these viruses, and due to their growing spread, several strategies have been employed to manufacture prophylactic vaccines against these infectious agents including virus-like particle (VLP) subunit vaccines. VLPs are genomeless viral particles that resemble authentic viruses and contain critical repetitive conformational structures on their surface that can trigger the induction of both humoral and cellular responses, making them safe and ideal vaccine candidates against these viruses. In this review, we focus on the potential of the VLP platform in the current vaccine development against the medically important viruses in the Flaviviridae family.
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Abstract
Japanese encephalitis is a mosquito-borne disease that occurs in Asia and is caused by Japanese encephalitis virus (JEV), a member of the genus Flavivirus. Although many flaviviruses can cause encephalitis, JEV causes particularly severe neurological manifestations. The virus causes loss of more disability-adjusted life years than any other arthropod-borne virus owing to the frequent neurological sequelae of the condition. Despite substantial advances in our understanding of Japanese encephalitis from in vitro studies and animal models, studies of pathogenesis and treatment in humans are lagging behind. Few mechanistic studies have been conducted in humans, and only four clinical trials of therapies for Japanese encephalitis have taken place in the past 10 years despite an estimated incidence of 69,000 cases per year. Previous trials for Japanese encephalitis might have been too small to detect important benefits of potential treatments. Many potential treatment targets exist for Japanese encephalitis, and pathogenesis and virological studies have uncovered mechanisms by which these drugs could work. In this Review, we summarize the epidemiology, clinical features, prevention and treatment of Japanese encephalitis and focus on potential new therapeutic strategies, based on repurposing existing compounds that are already suitable for human use and could be trialled without delay. We use our newly improved understanding of Japanese encephalitis pathogenesis to posit potential treatments and outline some of the many challenges that remain in tackling the disease in humans.
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27
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Honjo S, Masuda M, Ishikawa T. Effects of the Japanese Encephalitis Virus Genotype V-Derived Sub-Viral Particles on the Immunogenicity of the Vaccine Characterized by a Novel Virus-Like Particle-Based Assay. Vaccines (Basel) 2019; 7:vaccines7030081. [PMID: 31382680 PMCID: PMC6789769 DOI: 10.3390/vaccines7030081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/27/2019] [Accepted: 08/01/2019] [Indexed: 11/25/2022] Open
Abstract
Japanese encephalitis virus (JEV) is classified into five genotypes labelled I through V. Although the genotype V (GV) JEV was originally found and had apparently been limited in Malaysia for more than 50 years, its emergence in Korea and China has recently been reported. Therefore, the GV JEV might be spreading over new geographical regions as a cause of potential public health problems. However, it is unknown whether the currently available JEV vaccines are effective against the emerging GV strains. To investigate this issue, a novel virus-like particle-based neutralizing assay was developed in this study. By using this assay, the inactivated JEV vaccine used in Japan and the recombinant sub-viral particles (SVPs) bearing the E protein of the GV Muar strain were characterized for the immunogenicity against the GV JEV. Although the inactivated vaccine alone failed to elicit a detectable level of neutralizing antibodies against the GV JEV, the vaccine added with the Muar-derived SVPs induced relatively high titers of neutralizing antibodies, associated with the efficient Th1 immune responses, against the GV JEV. The results indicate that addition of the GV JEV-derived antigens may be useful for developing the vaccine that is universally effective against JEV including the emerging GV strains.
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Affiliation(s)
- Sarah Honjo
- Department of Microbiology, Dokkyo Medical University School of Medicine, 880 Kita-kobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan
| | - Michiaki Masuda
- Department of Microbiology, Dokkyo Medical University School of Medicine, 880 Kita-kobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan
| | - Tomohiro Ishikawa
- Department of Microbiology, Dokkyo Medical University School of Medicine, 880 Kita-kobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan.
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28
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Hills SL, Walter EB, Atmar RL, Fischer M. Japanese Encephalitis Vaccine: Recommendations of the Advisory Committee on Immunization Practices. MMWR Recomm Rep 2019; 68:1-33. [PMID: 31518342 PMCID: PMC6659993 DOI: 10.15585/mmwr.rr6802a1] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This report updates the 2010 recommendations from the CDC Advisory Committee on Immunization Practices (ACIP) regarding prevention of Japanese encephalitis (JE) among U.S. travelers and laboratory workers (Fischer M, Lindsey N, Staples JE, Hills S. Japanese encephalitis vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2010;59[No. RR-1]). The report summarizes the epidemiology of JE, describes the JE vaccine that is licensed and available in the United States, and provides recommendations for its use among travelers and laboratory workers.JE virus, a mosquitoborne flavivirus, is the most common vaccine-preventable cause of encephalitis in Asia. JE occurs throughout most of Asia and parts of the western Pacific. Approximately 20%-30% of patients die, and 30%-50% of survivors have neurologic, cognitive, or behavioral sequelae. No antiviral treatment is available.Inactivated Vero cell culture-derived JE vaccine (Ixiaro [JE-VC]) is the only JE vaccine that is licensed and available in the United States. In 2009, the U.S. Food and Drug Administration (FDA) licensed JE-VC for use in persons aged ≥17 years; in 2013, licensure was extended to include children aged ≥2 months.Most travelers to countries where the disease is endemic are at very low risk for JE. However, some travelers are at increased risk for infection on the basis of their travel plans. Factors that increase the risk for JE virus exposure include 1) traveling for a longer period; 2) travel during the JE virus transmission season; 3) spending time in rural areas; 4) participating in extensive outdoor activities; and 5) staying in accommodations without air conditioning, screens, or bed nets. All travelers to countries where JE is endemic should be advised to take precautions to avoid mosquito bites to reduce the risk for JE and other vectorborne diseases. For some persons who might be at increased risk for JE, the vaccine can further reduce the risk for infection. The decision about whether to vaccinate should be individualized and consider the 1) risks related to the specific travel itinerary, 2) likelihood of future travel to countries where JE is endemic, 3) high morbidity and mortality of JE, 4) availability of an effective vaccine, 5) possibility (but low probability) of serious adverse events after vaccination, and 6) the traveler's personal perception and tolerance of risk.JE vaccine is recommended for persons moving to a JE-endemic country to take up residence, longer-term (e.g., ≥1 month) travelers to JE-endemic areas, and frequent travelers to JE-endemic areas. JE vaccine also should be considered for shorter-term (e.g., <1 month) travelers with an increased risk for JE on the basis of planned travel duration, season, location, activities, and accommodations and for travelers to JE-endemic areas who are uncertain about their specific travel duration, destinations, or activities. JE vaccine is not recommended for travelers with very low-risk itineraries, such as shorter-term travel limited to urban areas or outside of a well-defined JE virus transmission season.
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Shinohara N, Owada T, Matsumoto C, Uchida S, Nagai T, Satake M, Tadokoro K. Evaluation of the protective ability of plasma from Japanese individuals against mosquito-borne viral infections. Trans R Soc Trop Med Hyg 2019; 111:393-401. [PMID: 29294131 DOI: 10.1093/trstmh/trx071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 11/06/2017] [Indexed: 11/15/2022] Open
Abstract
Background Most of the Japanese population is seropositive for anti-Japanese encephalitis virus (JEV) antibodies because of previous JEV vaccination or natural infection. Because the virological characteristics of JEV are similar to those of West Nile virus (WNV) and dengue virus (DENV), we hypothesized that anti-JEV antibodies can cross-react with WNV and DENV antigens, leading to protection against infection by these viruses. Methods Using isolated intravenous immunoglobulin (IVIG) from plasma collected in Japan, neutralizing activities against WNV and DENV and antibody-dependent enhancement (ADE) of these viral infections were evaluated using an in vitro assay to determine the potency of immunity against these viruses. Results The prepared IVIG showed considerable neutralizing activity of 2.57 log10 reduction factor against WNV infection but showed little effect against DENV infection. A strong correlation was observed between the neutralizing activity of individual plasma samples against JEV and WNV (ρ=0.768). Moreover, IVIG showed no significant ADE of WNV infection. Conclusions Based on these results, we presume that the Japanese population is generally protected from WNV infection. Furthermore, IVIG prepared from plasma donations from Japanese individuals is expected to be an effective therapeutic agent based on its neutralizing activity against JEV and WNV.
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Affiliation(s)
- Naoya Shinohara
- Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan
| | - Takashi Owada
- Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan
| | - Chieko Matsumoto
- Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan
| | - Shigeharu Uchida
- Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan
| | - Tadashi Nagai
- Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan
| | - Masahiro Satake
- Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan
| | - Kenji Tadokoro
- Central Blood Institute, Blood Service Headquarters, Japanese Red Cross Society, Tokyo, Japan
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30
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Barzon L, Palù G. Recent developments in vaccines and biological therapies against Japanese encephalitis virus. Expert Opin Biol Ther 2018; 18:851-864. [DOI: 10.1080/14712598.2018.1499721] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Luisa Barzon
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Giorgio Palù
- Department of Molecular Medicine, University of Padova, Padova, Italy
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31
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Fan YC, Chen JM, Lin JW, Chen YY, Wu GH, Su KH, Chiou MT, Wu SR, Yin JH, Liao JW, Chang GJJ, Chiou SS. Genotype I of Japanese Encephalitis Virus Virus-like Particles Elicit Sterilizing Immunity against Genotype I and III Viral Challenge in Swine. Sci Rep 2018; 8:7481. [PMID: 29748549 PMCID: PMC5945781 DOI: 10.1038/s41598-018-25596-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 03/21/2018] [Indexed: 01/04/2023] Open
Abstract
Swine are a critical amplifying host involved in human Japanese encephalitis (JE) outbreaks. Cross-genotypic immunogenicity and sterile protection are important for the current genotype III (GIII) virus-derived vaccines in swine, especially now that emerging genotype I (GI) JE virus (JEV) has replaced GIII virus as the dominant strain. Herein, we aimed to develop a system to generate GI JEV virus-like particles (VLPs) and evaluate the immunogenicity and protection of the GI vaccine candidate in mice and specific pathogen-free swine. A CHO-heparan sulfate-deficient (CHO-HS(-)) cell clone, named 51-10 clone, stably expressing GI-JEV VLP was selected and continually secreted GI VLPs without signs of cell fusion. 51-10 VLPs formed a homogeneously empty-particle morphology and exhibited similar antigenic activity as GI virus. GI VLP-immunized mice showed balanced cross-neutralizing antibody titers against GI to GIV viruses (50% focus-reduction micro-neutralization assay titers 71 to 240) as well as potent protection against GI or GIII virus infection. GI VLP-immunized swine challenged with GI or GIII viruses showed no fever, viremia, or viral RNA in tonsils, lymph nodes, and brains as compared with phosphate buffered saline-immunized swine. We thus conclude GI VLPs can provide sterile protection against GI and GIII viruses in swine.
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Affiliation(s)
- Yi-Chin Fan
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Jo-Mei Chen
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Jen-Wei Lin
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ying Chen
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Guan-Hong Wu
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Kuan-Hsuan Su
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Ming-Tang Chiou
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Shang-Rung Wu
- Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Ji-Hang Yin
- Graduate Institute of Veterinary Pathobiology, National Chung Hsing University, Taichung, Taiwan
| | - Jiunn-Wang Liao
- Graduate Institute of Veterinary Pathobiology, National Chung Hsing University, Taichung, Taiwan
| | - Gwong-Jen J Chang
- Arboviral Diseases Branch, Center for Disease Control and Prevention, Fort Collins, Colorado, United States of America
| | - Shyan-Song Chiou
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan.
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Hegde NR, Gore MM. Japanese encephalitis vaccines: Immunogenicity, protective efficacy, effectiveness, and impact on the burden of disease. Hum Vaccin Immunother 2017; 13:1-18. [PMID: 28301270 DOI: 10.1080/21645515.2017.1285472] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Japanese encephalitis (JE) is a serious public health concern in most of Asia. The disease is caused by JE virus (JEV), a flavivirus transmitted by Culex mosquitoes. Several vaccines have been developed to control JE in endemic areas as well as to protect travelers and military personnel who visit or are commissioned from non-endemic to endemic areas. The vaccines include inactivated vaccines produced in mouse brain or cell cultures, live attenuated vaccines, and a chimeric vaccine based on the live attenuated yellow fever virus 17D vaccine strain. All the marketed vaccines belong to the JEV genotype III, but have been shown to be efficacious against other genotypes and strains, with varying degrees of cross-neutralization, albeit at levels deemed to be protective. The protective responses have been shown to last three or more years, depending on the type of vaccine and the number of doses. This review presents a brief account of the different JE vaccines, their immunogenicity and protective ability, and the impact of JE vaccines in reducing the burden of disease in endemic countries.
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Affiliation(s)
- Nagendra R Hegde
- a Ella Foundation, Genome Valley , Turkapally, Shameerpet Mandal , Hyderabad , India
| | - Milind M Gore
- b National Institute of Virology, Indian Council of Medical Research , Pune , India
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Feroldi E, Boaz M, Yoksan S, Chokephaibulkit K, Thisyakorn U, Pancharoen C, Monfredo C, Bouckenooghe A. Persistence of Wild-Type Japanese Encephalitis Virus Strains Cross-Neutralization 5 Years After JE-CV Immunization. J Infect Dis 2017; 215:221-227. [PMID: 27815383 PMCID: PMC5439595 DOI: 10.1093/infdis/jiw533] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 10/28/2016] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The live-attenuated Japanese encephalitis (JE) vaccine (JE-CV; IMOJEV) induces a protective response in children. A shift in circulating JE virus strains suggests that a genotype shift phenomenon may occur throughout Southeast Asia. We assessed the neutralization of wild-type (WT) JE virus isolates at distal time points after vaccination. METHODS We analyzed serum samples from a subset of 47 children who had received a JE-CV booster after an inactivated JE vaccine primary immunization. We measured antibody titers (50% plaque reduction neutralization test) using a panel of WT JE strains at baseline, then after the booster at 28 days and 6 months in all subjects present at the time points and in a subset at year 5. Three additional recent isolates were tested at year 5. RESULTS Of 47 subjects, 43 (91.5%) subjects had JE neutralizing antibody titers ≥10 (reciprocal serum dilution) against the homologous strain before JE-CV boost; all were seroprotected up to year 5 after the JE-CV boost. Baseline WT seroprotection ranged between 78.7% and 87.2%; all subjects were seroprotected against the 4 WT strains at 28 days and 6 months; year 5 seroprotection ranged between 95.7% and 97.9%. Similar rates of protection against 3 additional WT isolates were observed at year 5. CONCLUSIONS The long-term immune responses induced after a JE-CV booster dose in toddlers were able to neutralize WT viruses from various genotypes circulating in Southeast Asia and India. CLINICAL TRIALS REGISTRATION NCT00621764.
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Affiliation(s)
| | - Mark Boaz
- Global Clinical Immunology, Sanofi Pasteur, Swiftwater, Pennsylvania
| | - Sutee Yoksan
- Center for Vaccine Development, Institute of Molecular Biosciences, Mahidol University, Thailand and Translational Research Unit, Chulabhorn Research Institute
| | | | - Usa Thisyakorn
- Department of Pediatrics, Chulalongkorn Hospital, Bangkok, Thailand
| | | | - Céline Monfredo
- Clinical Development, Sanofi Pasteur, Marcy l'Etoile, France
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Sasaki T, Kuwata R, Hoshino K, Isawa H, Sawabe K, Kobayashi M. Argonaute 2 Suppresses Japanese Encephalitis Virus Infection in Aedes aegypti. Jpn J Infect Dis 2016; 70:38-44. [PMID: 27169949 DOI: 10.7883/yoken.jjid.2015.671] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
There are three main innate immune mechanisms against viruses in mosquitoes. Infection with the flavivirus dengue virus is controlled by RNA interference (RNAi) and the JAK-STAT and Toll signaling pathways. This study showed that another flavivirus, Japanese encephalitis virus (JEV), did not invade the salivary glands of Aedes aegypti and that this may be a result of the innate immune resistance to the virus. Argonaute 2 (Ago2) plays a critical role in the RNAi pathway. To understand the mechanism of JEV resistance, we focused on Ago2 as a possible target of JEV. Here, we show that the expression of MyD88 (a mediator of Toll signaling) and Ago2 mRNAs was induced by JEV in the salivary glands of Ae. aegypti mosquitoes and that Ago2, JAK, and domeless (DOME) mRNAs were induced by JEV in the bodies of Ae. aegypti mosquitoes. Double-stranded (ds) Ago2 RNA enhanced JEV infection, and the virus was detected in salivary glands by immunofluorescence assay. In contrast, MyD88 dsRNA had no effect on JEV infection. These data suggest that Ago2 plays a crucial role in mediating the innate immune response of Ae. aegypti to JEV in a manner similar to that employed by dengue virus.
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Affiliation(s)
- Toshinori Sasaki
- Department of Medical Entomology, National Institute of Infectious Disease
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Cao L, Fu S, Gao X, Li M, Cui S, Li X, Cao Y, Lei W, Lu Z, He Y, Wang H, Yan J, Gao GF, Liang G. Low Protective Efficacy of the Current Japanese Encephalitis Vaccine against the Emerging Genotype 5 Japanese Encephalitis Virus. PLoS Negl Trop Dis 2016; 10:e0004686. [PMID: 27139722 PMCID: PMC4854478 DOI: 10.1371/journal.pntd.0004686] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/13/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The current Japanese encephalitis (JE) vaccine derived from G3 JE virus (JEV) can induce protective immunity against G1-G4 JEV genotypes. However, protective efficacy against the emerging G5 genotype has not been reported. METHODS/PRINCIPAL FINDINGS Using in vitro and in vivo tests, biological phenotype and cross-immunoreactions were compared between G3 JEV and G5 JEV (wild strains). The PRNT90 method was used to detect neutralizing antibodies against different genotypes of JEV in JE vaccine-immunized subjects and JE patients. In JE vaccine-immunized mice, the lethal challenge protection rates against G3 and G5 JEV wild strains were 100% and 50%, respectively. The seroconversion rates (SCRs) of virus antibodies against G3 and G5 JEV among vaccinated healthy subjects were 100% and 35%, respectively. All clinically identified JE patients showed high levels of G3 JEV neutralizing antibodies (≥1:10-1280) with positive serum geometric mean titers (GMTs) of 43.2, while for G5 JEV, neutralizing antibody conversion rates were only 64% with positive serum GMTs of 11.14. Moreover, the positive rate of JEV neutralizing antibodies against G5 JEV in pediatric patients was lower than in adults. CONCLUSIONS/SIGNIFICANCE Low levels of neutralizing/protective antibodies induced by the current JE vaccine, based on the G3 genotype, were observed against the emerging G5 JEV genotype. Our results demonstrate the need for more detailed studies to reevaluate whether or not the apparent emergence of G5 JEV can be attributed to failure of the current vaccine to induce appropriate immune protectivity against this genotype of JEV.
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MESH Headings
- Animals
- Animals, Newborn
- Antibodies, Neutralizing/blood
- Antibodies, Viral/blood
- Cell Line
- Cricetinae
- Cross Protection
- Cytopathogenic Effect, Viral
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/immunology
- Encephalitis Virus, Japanese/physiology
- Encephalitis, Japanese/immunology
- Encephalitis, Japanese/prevention & control
- Encephalitis, Japanese/virology
- Female
- Genotype
- Humans
- Immunogenicity, Vaccine
- Immunoglobulin M/blood
- Japanese Encephalitis Vaccines/administration & dosage
- Japanese Encephalitis Vaccines/immunology
- Male
- Mice
- Mice, Inbred BALB C
- Vaccines, Attenuated/administration & dosage
- Vaccines, Attenuated/immunology
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Affiliation(s)
- Lei Cao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Shihong Fu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Xiaoyan Gao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Minghua Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Shiheng Cui
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Xiaolong Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Yuxi Cao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Wenwen Lei
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Zhi Lu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Ying He
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Huanyu Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Jinghua Yan
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - George Fu Gao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
- * E-mail: (GFG); (GL)
| | - Guodong Liang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
- * E-mail: (GFG); (GL)
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de Wispelaere M, Ricklin M, Souque P, Frenkiel MP, Paulous S, Garcìa-Nicolàs O, Summerfield A, Charneau P, Desprès P. A Lentiviral Vector Expressing Japanese Encephalitis Virus-like Particles Elicits Broad Neutralizing Antibody Response in Pigs. PLoS Negl Trop Dis 2015; 9:e0004081. [PMID: 26437302 PMCID: PMC4593544 DOI: 10.1371/journal.pntd.0004081] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 08/21/2015] [Indexed: 01/08/2023] Open
Abstract
Background Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in Southeast Asia. Vaccination of domestic pigs has been suggested as a “one health” strategy to reduce viral disease transmission to humans. The efficiency of two lentiviral TRIP/JEV vectors expressing the JEV envelope prM and E glycoproteins at eliciting protective humoral response was assessed in a mouse model and piglets. Methodology/Principal Findings A gene encoding the envelope proteins prM and E from a genotype 3 JEV strain was inserted into a lentiviral TRIP vector. Two lentiviral vectors TRIP/JEV were generated, each expressing the prM signal peptide followed by the prM protein and the E glycoprotein, the latter being expressed either in its native form or lacking its two C-terminal transmembrane domains. In vitro transduction of cells with the TRIP/JEV vector expressing the native prM and E resulted in the efficient secretion of virus-like particles of Japanese encephalitis virus. Immunization of BALB/c mice with TRIP/JEV vectors resulted in the production of IgGs against Japanese encephalitis virus, and the injection of a second dose one month after the prime injection greatly boosted antibody titers. The TRIP/JEV vectors elicited neutralizing antibodies against JEV strains belonging to genotypes 1, 3, and 5. Immunization of piglets with two doses of the lentiviral vector expressing JEV virus-like particles led to high titers of anti-JEV antibodies, that had efficient neutralizing activity regardless of the JEV genotype tested. Conclusions/Significance Immunization of pigs with the lentiviral vector expressing JEV virus-like particles is particularly efficient to prime antigen-specific humoral immunity and trigger neutralizing antibody responses against JEV genotypes 1, 3, and 5. The titers of neutralizing antibodies elicited by the TRIP/JEV vector are sufficient to confer protection in domestic pigs against different genotypes of JEV and this could be of a great utility in endemic regions where more than one genotype is circulating. Japanese encephalitis virus is the etiologic agent of the most medically important viral encephalitis in South Asia with thousands of deaths per year. The virus is maintained in an enzootic cycle between Culex mosquitoes and amplifying vertebrate hosts, such as wild boars and pigs. Vaccination of domestic pigs has been suggested as a strategy to reduce viral disease transmission to humans, in line with the now-called “One Health” concept. Lentiviral gene transfer vectors represent a novel vaccination platform with an unprecedented ability to induce robust humoral immunity in various animal species. In our study, we demonstrated that immunization of pigs with a recombinant lentiviral vector expressing virus-like particles of Japanese encephalitis virus is particularly efficient at eliciting specific humoral immunity. The titers of neutralizing antibodies elicited by the lentiviral vector are sufficient to confer protection in domestic pigs against the different genotypes of Japanese encephalitis virus observed in Asia.
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Affiliation(s)
| | - Meret Ricklin
- Institute of Virology and Immunology, Mittelhäusern, Switzerland
| | - Philippe Souque
- Virologie Moléculaire et Vaccinologie, Institut Pasteur, Paris, France
| | | | - Sylvie Paulous
- Interactions Moléculaires Flavivirus-Hôtes, Institut Pasteur, Paris, France
| | | | - Artur Summerfield
- Institute of Virology and Immunology, Mittelhäusern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Pierre Charneau
- Virologie Moléculaire et Vaccinologie, Institut Pasteur, Paris, France
- * E-mail: (PC); (PD)
| | - Philippe Desprès
- Interactions Moléculaires Flavivirus-Hôtes, Institut Pasteur, Paris, France
- * E-mail: (PC); (PD)
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Erra EO, Kantele A. The Vero cell-derived, inactivated, SA14-14-2 strain-based vaccine (Ixiaro) for prevention of Japanese encephalitis. Expert Rev Vaccines 2015; 14:1167-79. [PMID: 26162529 DOI: 10.1586/14760584.2015.1061939] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
With an estimated 68,000 cases each year, Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Vaccination against the disease is recommended for endemic populations and also for travelers at risk. Recently, a Vero cell-derived, inactivated, SA14-14-2 strain-based JE vaccine (JE-VC) became available for travelers from non-endemic regions, replacing the traditional mouse brain-derived vaccines. First licensed in 2009, JE-VC is currently available in Europe, the USA, Canada, Australia and several other countries. In 2013, the vaccine was approved by the European Medicines Agency and the US Food and Drug Administration for use in children. This review summarizes current data on the immunogenicity, safety and clinical use of JE-VC.
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Affiliation(s)
- Elina O Erra
- Haartman Institute, University of Helsinki, Helsinki, Finland
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38
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Ulbert S, Magnusson SE. Technologies for the development of West Nile virus vaccines. Future Microbiol 2015; 9:1221-32. [PMID: 25405890 DOI: 10.2217/fmb.14.67] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
West Nile virus (WNV), an emerging mosquito-borne and zoonotic flavivirus, continues to spread worldwide and represents a major problem for human and veterinary medicine. In recent years, severe outbreaks were observed in the USA and Europe with neighboring countries, and the virus is considered to be endemic in an increasing number of areas. Although most infections remain asymptomatic, WNV can cause severe, even fatal, neurological disease, which affects mostly the elderly and immunocompromised individuals. Several vaccines have been licensed in the veterinary sector, but no human vaccine is available today. This review summarizes recent strategies that are being followed to develop WNV vaccines with emphasis on technologies suitable for the use in humans.
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Affiliation(s)
- Sebastian Ulbert
- Department of Immunology, Fraunhofer Institute for Cell Therapy & Immunology, Perlickstrasse 1, 04103 Leipzig, Germany
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39
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Abstract
As indicated by the sporadic Japanese encephalitis (JE) cases reported from the districts of Uttar Pradesh (UP), India, the disease is endemic in the state despite the fact that a JE vaccination programme has been ongoing in the state since 2006. Hence, the present study was undertaken to study the annual trend of JE in UP during January 2011 to December 2013. CSF and/or serum samples collected from acute encephalitis syndrome (AES) cases were referred to the virology laboratory at King George's Medical University, Lucknow and were tested for anti-JEV IgM antibodies by JEV MAC-ELISA kit. The study reveals that 26·9%, 9·9% and 14·8% of AES cases were positive for anti-JEV IgM in the years 2011, 2012 and 2013, respectively. Of the total JE confirmed cases, 30% were adults. Males were more commonly affected than females. A distinct peak of JE was seen in the monsoon and post-monsoon season, although sporadic cases were also reported in other months. JE vaccination by district in UP is discussed. This study reports that the proportion of JE positives in AES cases is decreasing in UP although the number of AES cases has not decreased. The study also discusses the probable causes of this decrease, including JE vaccination and natural periodicity due to herd immunity.
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40
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Khan SA, Borah J, Chowdhury P, Dutta P, Mahanta J. Characterization of Japanese encephalitis virus (JEV) genotype III clinical isolates in northeast India. Trans R Soc Trop Med Hyg 2015; 109:522-8. [DOI: 10.1093/trstmh/trv045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/19/2015] [Indexed: 11/12/2022] Open
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Abstract
Dengue is the most prevalent mosquito-borne viral disease worldwide. Yet, there are no vaccines or specific antivirals available to prevent or treat the disease. Several dengue vaccines are currently in clinical or preclinical stages. The most advanced vaccine is the chimeric tetravalent CYD-TDV vaccine of Sanofi Pasteur. This vaccine has recently cleared Phase III, and efficacy results have been published. Excellent tetravalent seroconversion was seen, yet the protective efficacy against infection was surprisingly low. Here, we will describe the complicating factors involved in the generation of a safe and efficacious dengue vaccine. Furthermore, we will discuss the human antibody responses during infection, including the epitopes targeted in humans. Also, we will discuss the current understanding of the assays used to evaluate antibody response. We hope this review will aid future dengue vaccine development as well as fundamental research related to the phenomenon of antibody-dependent enhancement of dengue virus infection.
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Affiliation(s)
- Jacky Flipse
- Department of Medical Microbiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jolanda M. Smit
- Department of Medical Microbiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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42
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Tajima S, Yagasaki K, Kotaki A, Tomikawa T, Nakayama E, Moi ML, Lim CK, Saijo M, Kurane I, Takasaki T. In vitro growth, pathogenicity and serological characteristics of the Japanese encephalitis virus genotype V Muar strain. J Gen Virol 2015; 96:2661-2669. [PMID: 26048886 DOI: 10.1099/vir.0.000213] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The characteristics of genotype V Japanese encephalitis virus (GV JEV) remain poorly understood as only two strains have been isolated to date. In this study, we examined the effects of the GV JEV Muar strain on in vitro growth and pathogenicity in mice; we also evaluated the efficacy of inactivated JEV vaccines against the Muar strain. Although growth of the Muar strain in mouse neuroblastoma N18 cells was clearly worse than that of the GIII Beijing-1 and GI Mie/41/2002 strains, neuroinvasiveness of the Muar strain was similar to that of the Beijing-1 strain and significantly higher than that of the Mie/41/2002 strain. The results of a plaque reduction neutralization test suggested that the neutralization ability of the JEV vaccines against the Muar strain was reduced compared with the GI and GIII strains. However, the protection potency of the JEV vaccine against the Muar strain was similar to that for the Beijing-1 strain in mice. Our data indicate that GV JEV has unique growth, virulence and antigenicity features.
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Affiliation(s)
- Shigeru Tajima
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Kazumi Yagasaki
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Akira Kotaki
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Takumi Tomikawa
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Eri Nakayama
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Meng Ling Moi
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Chang-Kweng Lim
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Masayuki Saijo
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Ichiro Kurane
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Tomohiko Takasaki
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
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Ye Q, Xu YP, Zhang Y, Li XF, Wang HJ, Liu ZY, Li SH, Liu L, Zhao H, Nian QG, Deng YQ, Qin ED, Qin CF. Genotype-specific neutralization determinants in envelope protein: implications for the improvement of Japanese encephalitis vaccine. J Gen Virol 2015; 96:2165-2175. [PMID: 25908779 DOI: 10.1099/vir.0.000160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Japanese encephalitis remains the leading cause of viral encephalitis in children in Asia and is expanding its geographical range to larger areas in Asia and Australasia. Five genotypes of Japanese encephalitis virus (JEV) co-circulate in the geographically affected areas. In particular, the emergence of genotype I (GI) JEV has displaced genotype III (GIII) as the dominant circulating genotype in many Asian regions. However, all approved vaccine products are derived from GIII strains. In the present study, bioinformatic analysis revealed that GI and GIII JEV strains shared two distinct amino acid residues within the envelope (E) protein (E222 and E327). By using reverse genetics approaches, A222S and S327T mutations were demonstrated to decrease live-attenuated vaccine (LAV) SA14-14-2-induced neutralizing antibodies in humans, without altering viral replication. A222S or S327T mutations were then rationally engineered into the infectious clone of SA14-14-2, and the resulting mutant strains retained the same genetic stability and attenuation characteristics as the parent strain. More importantly, immunization of mice with LAV-A222S or LAV-S327T elicited increased neutralizing antibodies against GI strains. Together, these results demonstrated that E222 and E327 are potential genotype-related neutralization determinants and are critical in determining the protective efficacy of live Japanese encephalitis vaccine SA14-14-2 against circulating GI strains. Our findings will aid in the rational design of the next generation of Japanese encephalitis LAVs capable of providing broad protection against all JEV strains belonging to different genotypes.
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Affiliation(s)
- Qing Ye
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yan-Peng Xu
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yu Zhang
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Xiao-Feng Li
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.,State Key Laboratory of Pathogen and Biosecurity, Beijing 100071, PR China
| | - Hong-Jiang Wang
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Zhong-Yu Liu
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Shi-Hua Li
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Long Liu
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.,Graduate School, Anhui Medical University, Hefei 230032, PR China
| | - Hui Zhao
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.,State Key Laboratory of Pathogen and Biosecurity, Beijing 100071, PR China
| | - Qing-Gong Nian
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yong-Qiang Deng
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - E-De Qin
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Cheng-Feng Qin
- Graduate School, Anhui Medical University, Hefei 230032, PR China.,Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.,State Key Laboratory of Pathogen and Biosecurity, Beijing 100071, PR China
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Singh A, Mitra M, Sampath G, Venugopal P, Rao JV, Krishnamurthy B, Gupta MK, Sri Krishna S, Sudhakar B, Rao NB, Kaushik Y, Gopinathan K, Hegde NR, Gore MM, Krishna Mohan V, Ella KM. A Japanese Encephalitis Vaccine From India Induces Durable and Cross-protective Immunity Against Temporally and Spatially Wide-ranging Global Field Strains. J Infect Dis 2015; 212:715-25. [PMID: 25601942 DOI: 10.1093/infdis/jiv023] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 01/06/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Japanese encephalitis (JE) is a vaccine-preventable acute disease. We report the results of a phase 2/3 trial of JENVAC, a Vero cell-derived vaccine developed using an Indian strain of JE virus (JEV). METHODS JENVAC was administered in 2 doses 28 days apart, and immunogenicity was compared to that from a single dose of SA-14-14-2, the only approved JE vaccine and regimen at the time in India. RESULTS After both the doses, seroconversion and seroprotection were >90% for JENVAC. For SA-14-14-2, seroconversion and seroprotection were 57.69% and 77.56%, respectively, on day 28 and 39.74% and 60.26%, respectively, on day 56. The geometric mean titers at day 28 and day 56 were 145.04 and 460.53, respectively, for JENVAC and 38.56 and 25.29, respectively, for SA-14-14-2. With a single dose of JENVAC, seroprotection titers lasted at least 12 months in >80% of the subjects. Following receipt of 2 doses, 61.17% of subjects retained seroprotection titers at 24 months, and immunogenicity criteria were higher than that for SA-14-14-2 at 12, 18, and 24 months each. Sera from JENVAC subjects neutralized JEV genotypes I, II, III, and IV equally well. Adverse events were not significantly different between the 2 vaccines. CONCLUSIONS JENVAC elicits long-lasting, broadly protective immunity. CLINICAL TRIALS REGISTRATION CTRI/2011/07/001855.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Milind M Gore
- Gorakhpur Unit, National Institute of Virology, India
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45
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Ye Q, Li XF, Zhao H, Deng YQ, Xu YP, Wang HY, Liang GD, Qin CF. Reduction of neutralization antibody against heterologous circulating strains in adults immunized with Japanese encephalitis live vaccine. Hum Vaccin Immunother 2014; 10:2704-5. [DOI: 10.4161/hv.29509] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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46
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Ishikawa T, Abe M, Masuda M. Construction of an infectious molecular clone of Japanese encephalitis virus genotype V and its derivative subgenomic replicon capable of expressing a foreign gene. Virus Res 2014; 195:153-61. [PMID: 25451067 DOI: 10.1016/j.virusres.2014.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/16/2014] [Accepted: 10/08/2014] [Indexed: 12/19/2022]
Abstract
Japanese encephalitis virus (JEV) genotype V was originally isolated in Malaysia in 1952 and has long been restricted to the area. In 2009, sudden emergence of the genotype V in China and Korea was reported, suggesting expansion of its geographical distribution. Although studies on the genotype V are becoming more important, they have been limited partly due to lack of its infectious molecular clone. In this study, a plasmid carrying cDNA corresponding to the entire genome of JEV Muar strain, which belongs to genotype V, in the downstream of T7 promoter was constructed. Electroporation of viral RNA transcribed by T7 RNA polymerase (T7RNAP) in vitro from the plasmid led to production of progeny viruses both in mammalian and mosquito cells. Also, transfection of the infectious clone plasmid into mammalian cells expressing T7RNAP transiently or stably was demonstrated to generate infectious progenies. When the viral structural protein genes were partially deleted from the full-length cDNA, the subgenomic RNA transcribed in vitro from the modified plasmid was shown to replicate itself in mammalian cells as a replicon. The replicon carrying the firefly luciferase gene in place of the deleted structural protein genes was also shown to efficiently replicate itself and express luciferase in mammalian cells. Compared with the replicon derived from JEV genotype III (Nakayama strain), the genotype V-derived replicon appeared to be more tolerant to introduction of a foreign gene. The infectious clone and the replicons constructed in this study may serve as useful tools for characterizing JEV genotype V.
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Affiliation(s)
- Tomohiro Ishikawa
- Department of Microbiology, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan.
| | - Makoto Abe
- Department of Microbiology, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan
| | - Michiaki Masuda
- Department of Microbiology, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan
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47
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Ishikawa T, Konishi E. Japanese encephalitis: epidemiology, prevention and current status of antiviral drug development. Expert Opin Orphan Drugs 2014. [DOI: 10.1517/21678707.2014.934222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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48
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Jelinek T. IXIARO updated: overview of clinical trials and developments with the inactivated vaccine against Japanese encephalitis. Expert Rev Vaccines 2014; 12:859-69. [PMID: 23984958 DOI: 10.1586/14760584.2013.835638] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The mosquito-borne Japanese encephalitis virus causes an estimated 50,000 cases in Asia, accounting for at least 10,000 deaths and 15,000 cases of neuropsychiatric sequelae. IXIARO (Intercell AG, Vienna, Austria), an inactivated, Vero cell-derived vaccine against Japanese encephalitis was introduced in 2009. The vaccine is highly immunogenic, showing significantly higher geometric mean antibody titers compared with previous, mouse brain-derived vaccines. Postmarketing studies have confirmed the excellent safety profile. Studies on children aged 2 months to 18 years have been published. Based on these data, positive opinion from the EMA for vaccination of children has recently been given. Since a safe and effective vaccine against Japanese encephalitis is now available, outdated guidelines and recommendations have to be revised: travelers to rural areas of Asia should generally be recommended vaccination.
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Affiliation(s)
- Tomas Jelinek
- Berlin Center for Travel and Tropical Medicine, Jägerstrasse 67-69, 10117 Berlin, Germany.
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Bonaparte M, Dweik B, Feroldi E, Meric C, Bouckenooghe A, Hildreth S, Hu B, Yoksan S, Boaz M. Immune response to live-attenuated Japanese encephalitis vaccine (JE-CV) neutralizes Japanese encephalitis virus isolates from south-east Asia and India. BMC Infect Dis 2014; 14:156. [PMID: 24656175 PMCID: PMC3994458 DOI: 10.1186/1471-2334-14-156] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 03/14/2014] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND During clinical development of the licensed Japanese encephalitis chimeric virus vaccine (JE-CV), the neutralization capacity of vaccine-induced antibodies was assessed against the vaccine virus and against well characterized wild-type (wt) viruses isolated between 1949-1991. We assessed whether JE-CV-induced antibodies can also neutralize more recent wt Japanese encephalitis virus (JEV) isolates including a genotype 1 isolate. METHODS Sera from 12-18 month-old children who received a single dose of JE-CV in a phase III study in Thailand and the Philippines (ClinicalTrials.gov NCT00735644) were randomly selected and pooled according to neutralization titer against JE-CV into eight samples. Neutralization was assessed by plaque reduction neutralization tests (PRNT50) against three recent isolates from JEV genotypes 1 and 3 in addition to four JEV previously tested. RESULTS Neutralization titers against the three recent JEV strains were comparable to those observed previously against other strains and the vaccine virus. The observed differences between responses to genotype 1 and 3 viruses were within assay variability for the PRNT50. CONCLUSIONS The results were consistent with previously generated data on the neutralization of wt JEV isolates, immune responses induced by JE-CV neutralize recently isolated virus from southeast (SE) Asia and India.
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Affiliation(s)
- Matthew Bonaparte
- Sanofi Pasteur Global Clinical Immunology Department, Swiftwater, USA
| | - Bashir Dweik
- Sanofi Pasteur Global Clinical Immunology Department, Swiftwater, USA
| | - Emmanuel Feroldi
- Sanofi Pasteur Clinical Development Department, Marcy l’Etoile, France
| | - Claude Meric
- Sanofi Pasteur Clinical Development Department, Marcy l’Etoile, France
| | | | - Stephen Hildreth
- Sanofi Pasteur Global Clinical Immunology Department, Swiftwater, USA
| | - Branda Hu
- Sanofi Pasteur Global Clinical Immunology Department, Swiftwater, USA
| | - Sutee Yoksan
- Center for Vaccine Development, Institute of Molecular Bioscience, Mahidol University, Bangkok, Thailand
| | - Mark Boaz
- Sanofi Pasteur Global Clinical Immunology Department, Swiftwater, USA
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50
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A review of successful flavivirus vaccines and the problems with those flaviviruses for which vaccines are not yet available. Vaccine 2014; 32:1326-37. [PMID: 24486372 DOI: 10.1016/j.vaccine.2014.01.040] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 01/11/2014] [Accepted: 01/15/2014] [Indexed: 12/19/2022]
Abstract
Genus flavivirus comprises many important human pathogens causing public health problems worldwide. Some flavivirus infections are characterized by a relatively high mortality rate and/or high sequelae rate in survivors. Because most flavivirus life cycles are maintained between arthropod vectors and amplifying/reservoir hosts in the absence of humans, eradication of flaviviruses might be extremely difficult. Flavivirus vaccine development is considered a reasonable method to prevent flavivirus infections. Some vaccines have been successfully developed, but others have not, regardless of much effort. This review article describes currently available flavivirus vaccines against yellow fever, Japanese encephalitis, and tick-borne encephalitis. In addition, the current status of dengue and West Nile virus vaccine development is reviewed and problems regarding their development are discussed.
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