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Shinjoh M, Togo K, Hayamizu T, Yonemoto N, Morii J, Perdrizet J, Kamei K. Cost-effectiveness analysis of 20-valent pneumococcal conjugate vaccine for routine pediatric vaccination programs in Japan. Expert Rev Vaccines 2024; 23:485-497. [PMID: 38682661 DOI: 10.1080/14760584.2024.2345670] [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: 01/17/2024] [Accepted: 04/17/2024] [Indexed: 05/01/2024]
Abstract
BACKGROUND The Japanese National Immunization Program currently includes the pediatric 13 valent pneumococcal conjugate vaccine (PCV13) to prevent pneumococcal infections. We aimed to evaluate the cost-effectiveness of 20-valent PCV (PCV20) as a pediatric vaccine versus PCV13. METHODS A decision-analytic Markov model was used to estimate expected costs, quality-adjusted life-years (QALYs), and prevented cases and deaths caused by invasive pneumococcal disease, pneumonia, and acute otitis media over a ten-year time horizon from the societal and healthcare payer perspectives. RESULTS PCV20 was dominant, i.e. less costly and more effective, over PCV13 (gained 294,599 QALYs and reduced Japanese yen [JPY] 352.6 billion [2.6 billion United States dollars, USD] from the societal perspective and JPY 178.9 billion [USD 1.4 billion] from the payer perspective). Sensitivity and scenario analyses validated the robustness of the base scenario results. When comparing PCV20 with PCV13, the threshold analysis revealed an incremental cost-effectiveness ratio that was within the threshold value (JPY 5 million/QALY) at a maximum acquisition cost of JPY 74,033 [USD 563] (societal perspective) and JPY 67,758 [USD 515] (payer perspective). CONCLUSIONS As a pediatric vaccine, PCV20 was dominant over PCV13 regardless of the study perspective.
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Affiliation(s)
- Masayoshi Shinjoh
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Kanae Togo
- Health and Value, Pfizer Japan Inc, Tokyo, Japan
| | | | | | - Junko Morii
- HEOR, Real World Evidence, IQVIA Solutions G.K, Tokyo, Japan
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Méroc E, Fletcher MA, Hanquet G, Slack MPE, Baay M, Hayford K, Gessner BD, Grant LR. Systematic Literature Review of the Epidemiological Characteristics of Pneumococcal Disease Caused by the Additional Serotypes Covered by the 20-Valent Pneumococcal Conjugate Vaccine. Microorganisms 2023; 11:1816. [PMID: 37512988 PMCID: PMC10383425 DOI: 10.3390/microorganisms11071816] [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: 04/26/2023] [Revised: 07/06/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Higher valency pneumococcal conjugate vaccines (PCV15 and PCV20) have been developed to address the disease burden of current non-vaccine serotypes. This review describes the epidemiological characteristics of serotypes beyond PCV13 (serotypes 8, 10A, 11A, 12F, 15B/C, 22F, and 33F; PCV20nonPCV13 serotypes). Peer-reviewed studies published between 1 January 2010 (the year PCV13 became available) and 18 August 2020 were systematically reviewed (PROSPERO number: CRD42021212875). Data describing serotype-specific outcomes on disease proportions, incidence, severity, and antimicrobial non-susceptibility were summarized for individual and aggregate PCV20nonPCV13 serotypes by age group and by type and duration of pediatric PCV immunization program. Of 1168 studies, 127 (11%) were included in the analysis. PCV20nonPCV13 serotypes accounted for 28% of invasive pneumococcal disease (IPD), although the most frequent serotypes differed between children (10A, 15B/C) and adults (8, 12F, 22F). In children, serotype 15B/C tended to be more frequently associated with pneumococcal meningitis and acute otitis media; in adults, serotype 8 was more frequently associated with pneumonia and serotype 12F with meningitis. Serotypes 10A and 15B/C in children and 11A and 15B/C in adults were often associated with severe IPD. Serotype 15B/C was also among the most frequently identified penicillin/macrolide non-susceptible PCV20nonPCV13 serotypes. These results could inform decision making about higher valency PCV choice and use.
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Affiliation(s)
- Estelle Méroc
- P95 Epidemiology & Pharmacovigilance, Koning Leopold III-laan 1, 3001 Leuven, Belgium
| | - Mark A Fletcher
- Emerging Markets Medical Affairs, Vaccines, Pfizer, 23-25 Av. du Dr Lannelongue, 75014 Paris, France
| | - Germaine Hanquet
- P95 Epidemiology & Pharmacovigilance, Koning Leopold III-laan 1, 3001 Leuven, Belgium
| | - Mary P E Slack
- School of Medicine & Dentistry, Griffith University Gold Coast Campus, Parklands Drive, Southport, QLD 4222, Australia
| | - Marc Baay
- P95 Epidemiology & Pharmacovigilance, Koning Leopold III-laan 1, 3001 Leuven, Belgium
| | - Kyla Hayford
- Medical Development and Scientific Clinical Affairs, Pfizer Vaccines, 500 Arcola Road, Collegeville, PA 19426, USA
| | - Bradford D Gessner
- Medical Development and Scientific Clinical Affairs, Pfizer Vaccines, 500 Arcola Road, Collegeville, PA 19426, USA
| | - Lindsay R Grant
- Medical Development and Scientific Clinical Affairs, Pfizer Vaccines, 500 Arcola Road, Collegeville, PA 19426, USA
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Mohanty S, Hu T, Yang G, Khan TK, Owusu-Edusei K, Sukarom I. Health and economic burden associated with 15-valent pneumococcal conjugate vaccine serotypes in Korea and Hong Kong. Hum Vaccin Immunother 2022; 18:2046433. [PMID: 35420975 PMCID: PMC9196648 DOI: 10.1080/21645515.2022.2046433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Use of pneumococcal conjugate vaccines (PCVs) has greatly reduced the incidence of invasive pneumococcal disease (IPD). V114 (VAXNEUVANCE™, Merck Sharp & Dohme Corp. a subsidiary of Merck & Co. Inc. Kenilworth, NJ, USA) is a 15-valent PCV currently approved in adults in the United States, containing the 13 serotypes in licensed PCV13 and 2 additional serotypes (22F and 33F) which are important contributors to residual pneumococcal disease. This study quantified the health and economic burden of IPD attributable to V114 serotypes in hypothetical birth cohorts from Korea and Hong Kong. A Markov model was used to estimate the case numbers and costs of IPD in unvaccinated birth cohorts over 20 years. The model was applied to 3 scenarios in Korea (pre-PCV7, pre-PCV13, and post-PCV13) and to 2 scenarios in Hong Kong (pre-PCV7 and post-PCV13). For Korea, the model predicted 62, 26, and 8 IPD cases attributable to V114 serotypes in the pre-PCV7, pre-PCV13, and post-PCV13 scenarios, respectively. Costs of V114-type IPD fell from $1.691 million pre-PCV7 to $.212 million post-PCV13. For Hong Kong, the model estimated 62 V114-associated IPD cases in the pre-PCV7 scenario and 46 in the post-PCV13 scenario. Costs attributed to all V114 serotypes were $2.322 million and $1.726 million in the pre-PCV7 and post-PCV13 periods, respectively. Vaccine-type serotypes are predicted to cause continuing morbidity and cost in Korea (19A) and Hong Kong (3 and 19A). New pediatric pneumococcal vaccines must continue to protect against serotypes in licensed vaccines to maintain disease reduction, while extending coverage to non-vaccine serotypes.
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Affiliation(s)
- Salini Mohanty
- Center for Observational and Real-World Evidence (CORE), Merck & Co., Inc., Kenilworth, NJ, USA
| | - Tianyan Hu
- Center for Observational and Real-World Evidence (CORE), Merck & Co., Inc., Kenilworth, NJ, USA
| | | | - Tsz K Khan
- Global Medical and Scientific Affairs, MSD, Hong Kong, China
| | - Kwame Owusu-Edusei
- Biostatistics & Research Decision Sciences (BARDS), Merck & Co., Inc., Kenilworth, NJ, USA
| | - Isaya Sukarom
- Center for Observational and Real-World Evidence (CORE), MSD Thailand, Bangkok, Thailand
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Kang HM, Kang JH. Effects of nasopharyngeal microbiota in respiratory infections and allergies. Clin Exp Pediatr 2021; 64:543-551. [PMID: 33872488 PMCID: PMC8566799 DOI: 10.3345/cep.2020.01452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 04/02/2021] [Indexed: 11/27/2022] Open
Abstract
The human microbiome, which consists of a collective cluster of commensal, symbiotic, and pathogenic microorganisms living in the human body, plays a key role in host health and immunity. The human nasal cavity harbors commensal bacteria that suppress the colonization of opportunistic pathogens. However, dysbiosis of the nasal microbial community is associated with many diseases, such as acute respiratory infections including otitis media, sinusitis and bronchitis and allergic respiratory diseases including asthma. The nasopharyngeal acquisition of pneumococcus, which exists as a pathobiont in the nasal cavity, is the initial step in virtually all pneumococcal diseases. Although the factors influencing nasal colonization and elimination are not fully understood, the adhesion of opportunistic pathogens to nasopharyngeal mucosa receptors and the eliciting of immune responses in the host are implicated in addition to bacterial microbiota properties and colonization resistance dynamics. Probiotics or synbiotic interventions may show promising and effective roles in the adjunctive treatment of dysbiosis; however, more studies are needed to characterize how these interventions can be applied in clinical practice in the future.
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Affiliation(s)
- Hyun Mi Kang
- Division of Pediatric Infectious Diseases, Departments of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jin Han Kang
- Division of Pediatric Infectious Diseases, Departments of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Yun KW, Rhie K, Kang JH, Kim KH, Ahn JG, Kim YJ, Eun BW, Oh SH, Cho HK, Hong YJ, Kim NH, Kim YK, Lee H, Lee T, Kim HM, Cho EY, Kim CS, Park SE, Oh CE, Jo DS, Song ES, Lee J, Choi JH, Lee JK, Lee HJ, Choi EH. Emergence of serotype 10A-ST11189 among pediatric invasive pneumococcal diseases, South Korea, 2014-2019. Vaccine 2021; 39:5787-5793. [PMID: 34465475 DOI: 10.1016/j.vaccine.2021.08.072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
Replacement with nonvaccine serotypes (NVTs) among invasive pneumococcal diseases (IPDs) after the introduction of extended-valency pneumococcal conjugate vaccines varies in predominant serotypes across countries. This study analyzed changes in serotype distribution through serotyping, multilocus sequence typing, and antimicrobial susceptibility testing of 168 pediatric IPD isolates obtained from a multihospital-based surveillance system during 2014-2019 in South Korea. Vaccine serotypes (VTs) accounted for 16.1% (19A, 10.1%; 6A, 1.8%; and 19F 1.8%), 82.1% were NVTs (10A, 23.8%; 15A, 8.3%; 12F, 6.5%; 15C, 6.5%; and 15B, 6.0%), and three (1.8%) were nontypeable. Serotype 10A was the most common serotype, with a significant increase from 11.5% in 2014 to 33.3% in 2019 (p < 0.05 for the trend). Other NVTs decreased from 70.4% to 41.7% between 2015 and 2019, most notably in serotype 12F (from 14.8% to 0%). Almost all (95.0%) serotype 10A isolates were ST11189, which were multidrug resistant.
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Affiliation(s)
- Ki Wook Yun
- Seoul National University College of Medicine, Seoul, South Korea
| | - Kyuyol Rhie
- Seoul National University College of Medicine, Seoul, South Korea
| | - Jin Han Kang
- The Catholic University of Korea College of Medicine, Seoul, South Korea
| | - Kyung-Hyo Kim
- Ewha Womans University School of Medicine, Seoul, South Korea
| | - Jong Gyun Ahn
- Yonsei University College of Medicine, Seoul, South Korea
| | - Yae-Jean Kim
- Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, South Korea
| | | | - Sung Hee Oh
- Hanyang University College of Medicine, Seoul, South Korea
| | - Hye-Kyung Cho
- Gachon University College of Medicine, Gil Medical Center, Incheon, South Korea
| | - Young Jin Hong
- Inha University School of Medicine, Incheon, South Korea
| | - Nam Hee Kim
- Inje University Ilsan Paik Hospital, Goyang, South Korea
| | - Yun-Kyung Kim
- Korea University College of Medicine, Seoul, South Korea
| | - Hyunju Lee
- Seoul National University College of Medicine, Seoul, South Korea; Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Taekjin Lee
- CHA University CHA Bundang Medical Center, Seongnam, South Korea
| | - Hwang Min Kim
- Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Eun Young Cho
- Chungnam National University Hospital, Daejeon, South Korea
| | - Chun Soo Kim
- Keimyung University School of Medicine, Daegu, South Korea
| | - Su Eun Park
- Pusan National University School of Medicine, Yangsan, South Korea
| | - Chi Eun Oh
- Kosin University College of Medicine, Busan, South Korea
| | - Dae Sun Jo
- Jeonbuk National University Medical School, Jeonju, South Korea
| | - Eun Song Song
- Chonnam National University Medical School, Gwangju, South Korea
| | - Jina Lee
- University of Ulsan College of Medicine, Seoul, South Korea
| | - Jae Hong Choi
- Jeju National University School of Medicine, Jeju, South Korea
| | - Joon Kee Lee
- Chungbuk National University Hospital, Cheongju, South Korea
| | - Hoan Jong Lee
- Seoul National University College of Medicine, Seoul, South Korea
| | - Eun Hwa Choi
- Seoul National University College of Medicine, Seoul, South Korea.
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Kim HY, Park SB, Kang ES, Lee SM, Kim HJ, Wasserman M. Cost-effectiveness of a national immunization program with the 13-valent pneumococcal conjugate vaccine compared with the 10-valent pneumococcal conjugate vaccine in South Korea. Hum Vaccin Immunother 2020; 17:909-918. [PMID: 32783576 PMCID: PMC7993233 DOI: 10.1080/21645515.2020.1796426] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Introduction Globally, pneumococcal disease represents a significant burden. South Korea implemented the 7-valent pneumococcal conjugate vaccine (PCV7) in 2003, replaced with the 10-valent (PCV10) and 13-valent (PCV13) vaccine in 2010. In 2014, both vaccines were introduced in the national immunization program (NIP) for infants with 3 primary doses and one booster dose We performed a cost-effectiveness evaluation to elucidate which vaccine may be expected to provide greater impact if included in a NIP. Methodology Using an established model, we estimated the impact of introducing either PCV13 or PCV10 into the South Korean NIP in 2015. Vaccine impact was based on historic observed impact of PCV13 from 2010 to 2015 in Korea given high uptake of PCV13, and PCV10 impact was estimated based on experiences in countries using PCV10. Incidence and costs for all ages and including invasive pneumococcal disease, pneumonia, and acute otitis media were derived from the literature and Health Insurance Review and Assessment database. Results In the base-case, over 5-years PCV13 was estimated to avert 550,000 more cases of pneumococcal disease compared to PCV10, driven by broader serotype coverage and less replacement due to serotypes 3 and 19A. This translated to a cost-savings of $47.4 million USD despite PCV13’s higher cost. Sensitivity analysis found incremental cost-effectiveness ratios (ICERs) ranged from cost-saving to $7,300 USD per quality-adjusted life year (QALY). Conclusion A NIP using PCV13 was estimated to have a more substantial public health impact and be cost-saving compared to a program with PCV10 due to broader serotype coverage.
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Affiliation(s)
| | | | - Eun-Sil Kang
- Health Economics and Outcomes Research, Pfizer Ltd, Seoul, Korea
| | - Sang-Min Lee
- Health Economics and Outcomes Research, Pfizer Ltd, Seoul, Korea
| | | | - Matt Wasserman
- Health Economics and Outcomes Research, Pfizer Inc, New York, NY, USA
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Evaluation of the impact of 13-valent pneumococcal conjugate vaccine immunization in children by surveillance of culture-confirmed pneumococcal disease: A prospective clinical microbiological study. Vaccine 2019; 37:5147-5152. [PMID: 31377076 DOI: 10.1016/j.vaccine.2019.07.073] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 07/17/2019] [Accepted: 07/24/2019] [Indexed: 02/02/2023]
Abstract
The study aimed to investigate the impact of 13-valent pneumococcal conjugate vaccine (PCV13) immunization on the overall pneumococcal disease in children in Taiwan by surveillance of culture-confirmed pneumococcal disease (CCPD). This study was conducted in a medical center from 2012 to 2016. Clinical isolates of Streptococcus pneumoniae were prospectively collected from pediatric patients. Serotyping, multi-locus sequence typing, and antimicrobial susceptibility testing were performed. A total of 473 patients with CCPD, including 58 with invasive pneumococcal disease (IPD), were identified. The incidence of CCPD per 10,000 admissions decreased from 71.7 in 2012 to 27.0 in 2016. The proportion of additional PCV13 serotypes significantly decreased from 52.0% in 2012 to 21.7% in 2015 but increased slightly to 26.7% because of serotype 19A in 2016 (P < 0.0001). The proportion of non-vaccine serotypes (NVTs) increased significantly from 18.4% in 2012 to 66.7% in 2016, but the increase of the incidence of CCPD caused by NVTs was not considered significant (P = 0.0885). Genotyping identified predominant clones, ST6315A, ST8315B, and ST166/33823A, for major NVTs. The penicillin non-susceptibility of PCV13 serotypes was significantly higher than that of NVTs (P < 0.0001). Surveillance of CCPD appears superior to IPD alone for evaluation of the overall impact of pneumococcal immunization. Serotype replacement occurred quickly after the use of PCV13, while the incidence of NVT infection did not show a significant increase in children over the years. The gradual introduction of PCV13 into national immunization program is effective in reducing overall pneumococcal disease in children.
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Perniciaro S, Imöhl M, Fitzner C, van der Linden M. Regional variations in serotype distribution and vaccination status in children under six years of age with invasive pneumococcal disease in Germany. PLoS One 2019; 14:e0210278. [PMID: 30625215 PMCID: PMC6326516 DOI: 10.1371/journal.pone.0210278] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 12/19/2018] [Indexed: 12/04/2022] Open
Abstract
Overview The protective effect of infant pneumococcal conjugate vaccine (PCV) recommendation can be seen in Germany as a whole and in smaller regional groups. Comparisons between population-normalized geographic regions of Germany show different serotype distributions after program implementation, particularly in non-vaccine serotypes. The prior distinct differences in serotype distribution in children between the former East and former West German federal states have vanished. Children under six remain a vulnerable group, but the occurrence of vaccine-type (VT) invasive pneumococcal disease (IPD) in children correctly vaccinated (using a three-dose primary series plus one booster dose) with PCV13 was low (9 out of 374 cases, 2.4%). However, only 18.4% of children in Germany with IPD were correctly vaccinated with PCV13 according to the recommended schedule. Continued surveillance and better schedule adherence are essential to definitively establish the most effective PCV administration schedule. Vaccination effects For all PCV products used in Germany (PCV7, PCV10, and PCV13), vaccination status was the most common statistically significant predictor of infection with a particular serotype: Unvaccinated children old enough to have received at least one dose of vaccine in the PCV7 group had significantly higher odds (OR: 6.84, 95%CI: 2.66–22.06, adjusted for per capita income and residence in the northeastern federal states) of contracting VT IPD. In the PCV10 group, VT IPD had an OR of 4.52 (95% CI: 1.60–15.62, adjusted for year of infection, median household size, and residence in the southern federal states) in unvaccinated children, and in the PCV13 group, unvaccinated children continued to have higher odds (OR: 6.21, 95%CI: 3.45–11.36, adjusted for year of infection, age of child, per capita income, residence in the southern federal states, and percentage of children using public daycare) of getting vaccine-type IPD. Being unvaccinated was the most frequent significant indicator for infection with vaccine-type serotypes for each analysis group, while geographic groupings showed more limited potential to predict serotype of infection in early childhood IPD in Germany.
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Affiliation(s)
- Stephanie Perniciaro
- Department of Medical Microbiology, German National Reference Center for Streptococci, University Hospital (RWTH) Aachen, Germany
- * E-mail:
| | - Matthias Imöhl
- Department of Medical Microbiology, German National Reference Center for Streptococci, University Hospital (RWTH) Aachen, Germany
| | - Christina Fitzner
- Department of Medical Statistics, University Hospital (RWTH) Aachen, Germany
| | - Mark van der Linden
- Department of Medical Microbiology, German National Reference Center for Streptococci, University Hospital (RWTH) Aachen, Germany
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Genetic structures of invasive Streptococcus pneumoniae isolates from Korean children obtained between 1995 and 2013. BMC Infect Dis 2018; 18:268. [PMID: 29884115 PMCID: PMC5994121 DOI: 10.1186/s12879-018-3177-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 05/30/2018] [Indexed: 11/16/2022] Open
Abstract
Background Understanding the population genetics of pneumococci will allow detection of changes in the prevalence of circulating genotypes and evidence for capsular switching. We aimed to analyze the genetic structure of invasive pneumococcal isolates obtained from children before and after the use of pneumococcal conjugate vaccines (PCVs) in Korea. Methods A total of 285 invasive pneumococcal isolates were analyzed using serotyping, multilocus sequence typing, and antimicrobial susceptibility testing. We classified the isolation year to pre-PCV7 (1995–2003; n = 70), post-PCV7 (2004–2010; n = 142), and post-PCV13 (2011–2013; n = 73) periods. Results Of the 10 clonal complexes (CCs), antibiotic-resistant international clones, CC320 (31.6%), CC81 (14.7%), and CC166 (6.7%) were the main complexes. Serotype 19A was the main serotype of CC320 throughout the periods. Serotypes of CC81 mainly comprised of 23F (53.3%) in pre-PCV7 period and replaced by non-vaccine types (NVTs; 6C [10%], 13 [30%], 15A [40%], and 15B/C [20%]) in post-PCV13 period. The main serotype responsible for CC166 also changed from 9 V (80%) in pre-PCV7 to NVT 11A (50%) in post-PCV13 periods. Non-susceptibility to penicillin (42.3%) was the highest in CC320, increasing from 0 to 76%. Conclusion The genetic structures of invasive pneumococcal isolates in Korean children have changed concomitantly with serotype after the implementation of PCVs.
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Yun KW, Choi EH, Lee HJ. Genetic diversity of pneumococcal surface protein A in invasive pneumococcal isolates from Korean children, 1991-2016. PLoS One 2017; 12:e0183968. [PMID: 29131872 PMCID: PMC5683564 DOI: 10.1371/journal.pone.0183968] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 08/15/2017] [Indexed: 12/02/2022] Open
Abstract
Pneumococcal surface protein A (PspA) is an important virulence factor of pneumococci and has been investigated as a primary component of a capsular serotype-independent pneumococcal vaccine. Thus, we sought to determine the genetic diversity of PspA to explore its potential as a vaccine candidate. Among the 190 invasive pneumococcal isolates collected from Korean children between 1991 and 2016, two (1.1%) isolates were found to have no pspA by multiple polymerase chain reactions. The full length pspA genes from 185 pneumococcal isolates were sequenced. The length of pspA varied, ranging from 1,719 to 2,301 base pairs with 55.7–100% nucleotide identity. Based on the sequences of the clade-defining regions, 68.7% and 49.7% were in PspA family 2 and clade 3/family 2, respectively. PspA clade types were correlated with genotypes using multilocus sequence typing and divided into several subclades based on diversity analysis of the N-terminal α-helical regions, which showed nucleotide sequence identities of 45.7–100% and amino acid sequence identities of 23.1–100%. Putative antigenicity plots were also diverse among individual clades and subclades. The differences in antigenicity patterns were concentrated within the N-terminal 120 amino acids. In conclusion, the N-terminal α-helical domain, which is known to be the major immunogenic portion of PspA, is genetically variable and should be further evaluated for antigenic differences and cross-reactivity between various PspA types from pneumococcal isolates.
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Affiliation(s)
- Ki Wook Yun
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.,Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| | - Eun Hwa Choi
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.,Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
| | - Hoan Jong Lee
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.,Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
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