The 2nd China Vaccinology Integrated Innovation & Teaching Development Conference: Promoting the construction of vaccinology discipline system

The 2nd China Vaccinology Integrated Innovation & Teaching Development Conference was held in Sun Yat-sen University, Shenzhen, 18-19, November 2023. Over 200 participants in the field of Vaccinology gathered together to address challenges and issues relevant to vaccine education and training courses, research, and public health programs in China. The conference themed "Promoting the Integrated and Innovative Development of Vaccinology through Collective Efforts." The conference was organized by the China Association of Vaccine (CAV) and hosted by Vaccinology Education Professional Committee of CAV, and School of Public Health (Shenzhen), Sun Yat-sen University. Other partners included the Medical Virology Branch of the Chinese Medical Association, the editorial committee of the Chinese Journal of Preventive Medicine, Human Vaccines & Immunotherapeutics, and the People's Medical Publishing House. The 1st conference was held in Hangzhou, in October 2020.

Understanding the host response of farmed fish to blood flukes (Trematoda: Aporocotylidae) for developing new treatment strategies

Aporocotylids (Trematoda: Digenea), also known as fish blood flukes infect the circulatory system of fish leading to serious health problems and mortality. Aporocotylids are a particular concern for farmed fish as infection intensity can increase within the farming environment and lead to mortalities. In the context of managing these infections, one of the most crucial aspects to consider is the host response of the infected fish against these blood flukes. Understanding the response is essential to improving current treatment strategies that are largely based on the use of anthelmintic praziquantel to manage infections in aquaculture. This review focuses on the current knowledge of farmed fish host responses against the different life stages of aporocotylids. New treatment strategies that are able to provide protection against reinfections should be a long-term goal and is not possible without understanding the fish response to infection and the interactions between host and parasite.

Characterisation of protective vaccine antigens from the thiol-containing components of excretory/secretory material of Ostertagia ostertagi

Previous vaccination trials have demonstrated that thiol proteins affinity purified from Ostertagia ostertagi excretory-secretory products (O. ostertagi ES-thiol) are protective against homologous challenge. Here we have shown that protection induced by this vaccine was consistent across four independent vaccine-challenge experiments. Protection is associated with reduced cumulative faecal egg counts across the duration of the trials, relative to control animals. To better understand the diversity of antigens in O. ostertagi ES-thiol we used high-resolution shotgun proteomics to identify 490 unique proteins in the vaccine preparation. The most numerous ES-thiol proteins, with 91 proteins identified, belong to the sperm-coating protein/Tpx/antigen 5/pathogenesis-related protein 1 (SCP/TAPS) family. This family includes previously identified O. ostertagi vaccine antigens O. ostertagi ASP-1 and ASP-2. The ES-thiol fraction also has numerous proteinases, representing three distinct classes, including: metallo-; aspartyl- and cysteine proteinases. In terms of number of family members, the M12 astacin-like metalloproteinases, with 33 proteins, are the most abundant proteinase family in O. ostertagi ES-thiol. The O. ostertagi ES-thiol proteome provides a comprehensive database of proteins present in this vaccine preparation and will guide future vaccine antigen discovery projects.

A multivalent mRNA monkeypox virus vaccine (BNT166) protects mice and macaques from orthopoxvirus disease

In response to the 2022 outbreak of mpox driven by unprecedented human-to-human monkeypox virus (MPXV) transmission, we designed BNT166, aiming to create a highly immunogenic, safe, accessible, and scalable next-generation vaccine against MPXV and related orthopoxviruses. To address the multiple viral forms and increase the breadth of immune response, two candidate multivalent mRNA vaccines were evaluated pre-clinically: a quadrivalent vaccine (BNT166a; encoding the MPXV antigens A35, B6, M1, H3) and a trivalent vaccine (BNT166c; without H3). Both candidates induced robust T cell responses and IgG antibodies in mice, including neutralizing antibodies to both MPXV and vaccinia virus. In challenge studies, BNT166a and BNT166c provided complete protection from vaccinia, clade I, and clade IIb MPXV. Furthermore, immunization with BNT166a was 100% effective at preventing death and at suppressing lesions in a lethal clade I MPXV challenge in cynomolgus macaques. These findings support the clinical evaluation of BNT166, now underway (NCT05988203).

Natural infection by Zika virus but not DNA vaccination consistently elicits antibodies that compete with two potently neutralising monoclonal antibodies targeting distinct epitopes

BACKGROUND

Autochthonous transmission of Zika virus (ZIKV) has been reported in 87 countries since 2015. Although most infections are mild, there is risk of Guillain-Barré syndrome and adverse pregnancy outcomes. Vaccines are urgently needed to prevent Zika, but sufficient understanding of humoral responses and tools to assess ZIKV-specific immunity are lacking.

METHODS

We developed a blockade-of-binding (BOB) ELISA using A9E and G9E, two strongly neutralising ZIKV-specific monoclonal antibodies, which do not react with dengue virus. Receiver operating characteristic curve analysis assessed A9E and G9E BOB serodiagnostic performance. BOB was then applied to samples from a surveillance cohort in Risaralda, Colombia, and phase 1 ZIKV vaccine trial samples, comparing results against traditional serologic tests.

FINDINGS

In the validation sample set (n = 120), A9E BOB has a sensitivity of 93.5% (95% CI: 79.3, 98.9) and specificity 97.8 (95% CI: 92.2, 99.6). G9E BOB had a sensitivity of 100% (95% CI: 89.0, 100.0) and specificity 100% (95% CI: 95.9, 100). Serum from natural infections consistently tested positive in these assays for up to one year, and reactivity tracks well with ZIKV infection status among sera from endemic areas with complicated flavivirus exposures. Interestingly, a leading ZIKV vaccine candidate elicited minimal BOB reactivity despite generating neutralising antibody responses.

INTERPRETATION

In conclusion, A9E and G9E BOB assays are sensitive and specific assays for detecting antibodies elicited by recent or remote ZIKV infections. Given the additional ability of these BOB assays to detect immune responses that target different epitopes, further development of these assays is well justified for applications including flavivirus surveillance, translational vaccinology research and as potential serologic correlates of protective immunity against Zika.

FUNDING

R21 AI129532 (PI: S. Becker-Dreps), CDCBAA 2017-N-18041 (PI: A. M. de Silva), Thrasher Fund (PI: M. H. Collins), K22 AI137306 (PI: M. H. Collins).

Relapsing myocarditis following initial recovery of post COVID-19 vaccination in two adolescent males - Case reports

Whilst there has been significant public health benefits associated with global use of COVID-19 spike protein vaccines, potential serious adverse events following immunization have been reported. Acute myocarditis is a rare complication of COVID19 vaccines and often it is self-limiting. We describe two cases experiencing recurrent myocarditis following mRNA COVID-19 vaccine despite a prior episode with full clinical recovery. Between September 2021-September 2022 we observed two male adolescents with recurrent myocarditis related to mRNA-based-COVID19 vaccine. During the first episode both patients presented with fever and chest pain few days after their second dose of BNT162b2 mRNA Covid-19 Vaccine (Comirnaty®). The blood exams showed increased cardiac enzymes. In addition, complete viral panel was run, showing HHV7 positivity in a single case. The left ventricular ejection fraction (LVEF) was normal at echocardiogram but cardiac magnetic resonance scanning (CMR) was consistent with myocarditis. They were treated with supportive treatment with full recovery. The 6 months follow-up demonstrated good clinical conditions with normal cardiological findings. The CMR showed persistent lesions in left ventricle 's wall with LGE. After some months the patients presented at emergency department with fever and chest pain and increased cardiac enzymes. No decreased LVEF was observed. The CMR showed new focal areas of edema in the first case report and stable lesions in the second one. They reached full recovery with normalization of cardiac enzymes after few days. These case reports outline the need of strict follow-up in patients with CMR consistent with myocarditis after mRNA-based-COVID19 vaccine. More efforts are necessary to depict the underlying mechanisms of myocarditis after SARS-CoV2 vaccination to understand the risk of relapsing and the long-term sequelae.

Employing computational tools to design a multi-epitope vaccine targeting human immunodeficiency virus-1 (HIV-1)

BACKGROUND

Despite being in the 21^st century, the world has still not been able to vanquish the global AIDS epidemic, and the only foreseeable solution seems to be a safe and effective vaccine. Unfortunately, vaccine trials so far have returned unfruitful results, possibly due to their inability to induce effective cellular, humoral and innate immune responses. The current study aims to tackle these limitations and propose the desired vaccine utilizing immunoinformatic approaches that have returned promising results in designing vaccines against various rapidly mutating organisms. For this, all polyprotein and protein sequences of HIV-1 were retrieved from the LANL (Los Alamos National Laboratory) database. The consensus sequence was generated after alignment and used to predict epitopes. Conserved, antigenic, non-allergenic, T-cell inducing, B-cell inducing, IFN-ɣ inducing, non-human homologous epitopes were selected and combined to propose two vaccine constructs i.e., HIV-1a (without adjuvant) and HIV-1b (with adjuvant).

RESULTS

HIV-1a and HIV-1b were subjected to antigenicity, allergenicity, structural quality analysis, immune simulations, and MD (molecular dynamics) simulations. Both proposed multi-epitope vaccines were found to be antigenic, non-allergenic, stable, and induce cellular, humoral, and innate immune responses. TLR-3 docking and in-silico cloning of both constructs were also performed.

CONCLUSION

Our results indicate HIV-1b to be more promising than HIV-1a; experimental validations can confirm the efficacy and safety of both constructs and in-vivo efficacy in animal models.

Strategic construction of mRNA vaccine derived from conserved and experimentally validated epitopes of avian influenza type A virus: a reverse vaccinology approach

Purpose

The development of vaccines that confer protection against multiple avian influenza A (AIA) virus strains is necessary to prevent the emergence of highly infectious strains that may result in more severe outbreaks. Thus, this study applied reverse vaccinology approach in strategically constructing messenger RNA (mRNA) vaccine construct against avian influenza A (mVAIA) to induce cross-protection while targeting diverse AIA virulence factors.

Materials and Methods

Immunoinformatics tools and databases were utilized to identify conserved experimentally validated AIA epitopes. CD8⁺ epitopes were docked with dominant chicken major histocompatibility complexes (MHCs) to evaluate complex formation. Conserved epitopes were adjoined in the optimized mVAIA sequence for efficient expression in Gallus gallus. Signal sequence for targeted secretory expression was included. Physicochemical properties, antigenicity, toxicity, and potential cross-reactivity were assessed. The tertiary structure of its protein sequence was modeled and validated in silico to investigate the accessibility of adjoined B-cell epitope. Potential immune responses were also simulated in C-ImmSim.

Results

Eighteen experimentally validated epitopes were found conserved (Shannon index <2.0) in the study. These include one B-cell (SLLTEVETPIRNEWGCR) and 17 CD8⁺ epitopes, adjoined in a single mRNA construct. The CD8⁺ epitopes docked favorably with MHC peptide-binding groove, which were further supported by the acceptable ΔG_bind (-28.45 to -40.59 kJ/mol) and Kd (<1.00) values. The incorporated Sec/SPI (secretory/signal peptidase I) cleavage site was also recognized with a high probability (0.964814). Adjoined B-cell epitope was found within the disordered and accessible regions of the vaccine. Immune simulation results projected cytokine production, lymphocyte activation, and memory cell generation after the 1st dose of mVAIA.

Conclusion

Results suggest that mVAIA possesses stability, safety, and immunogenicity. In vitro and in vivo confirmation in subsequent studies are anticipated.

In silico design of a novel peptide-based vaccine against the ubiquitous apicomplexan Toxoplasma gondii using surface antigens

Human toxoplasmosis is a global public health concern and a commercial vaccine is still lacking. The present in silico study was done to design a novel vaccine candidate using tachyzoite-specific SAG1-realted sequence (SRS) proteins. Overlapping B-cell and strictly-chosen human MHC-I binding epitopes were predicted and connected together using appropriate spacers. Moreover, a TLR4 agonist, human high mobility group box protein 1 (HMGB1), and His-tag were added to the N- and C-terminus of the vaccine sequence. The final vaccine had 442 residues and a molecular weight of 47.71 kDa. Physico-chemical evaluation showed a soluble, highly antigenic and non-allergen protein, with coils and helices as secondary structures. The vaccine 3D model was predicted by ITASSER server, subsequently refined and was shown to possess significant interactions with human TLR4. As well, potent stimulation of cellular and humoral immunity was demonstrated upon chimeric vaccine injection. Finally, the outputs showed that this vaccine model possesses top antigenicity, which could provoke significant cell-mediated immune profile including IFN-γ, and can be utilized towards prophylactic purposes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-023-00140-w.

Protocol for a scoping review of potential vaccine candidates predicted by VaxiJen for different viral pathogens between 2017-2021

BACKGROUND

Vaccination is essential for the prevention of infectious diseases and has helped to reduce disease-related mortality, such as pneumonia. However, traditional vaccine development is time-consuming and risky. Reverse vaccinology (RV) is a promising alternative to developing vaccines based on the in silico discovery of antigens, often termed 'potential vaccine candidates' (PVCs), using a pathogen's proteome. RV prediction technologies, such as VaxiJen (founded in 2007), are used to take the first step toward vaccine development. VaxiJen is used by researchers to identify PVCs for various diseases. A 10-year review of these PVCs was published in 2017. There has since been no review of viral PVCs predicted by VaxiJen from 2017 to 2021. The proposed scoping review aims to address this gap.

METHODS

This protocol is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) 2015 checklist. The review will employ Arksey and O'Malley's five-stage methodological framework, which was later enhanced by Levac et al. and the Joanna Briggs Institute (JBI). The PRISMA extension for Scoping Reviews (PRISMA-ScR) reporting guideline will be utilized with this framework. PubMed, Scopus, Web of Science, EBSCOhost, and ProQuest One Academic will be searched using the term 'vaxijen'. The inclusion criteria will be English-only full-text original articles published in peer-reviewed journals and unpublished papers from 2017 to 2021. Rayyan will be used to deduplicate, screen titles and abstracts of articles. The articles' full texts will be examined. The data will be extracted using Microsoft Excel. Using a data charting form, data will be sifted and organized by key categories and themes.

DISCUSSION

This protocol was submitted for publication and went through an extensive peer review process. The review has implications for novel vaccine development against various viruses. The key limitation of this study is language bias due to the selection of English-only papers because of limited resources. This study will not require ethical clearance since it will use secondary data and will not include patients. Nevertheless, this research is part of a larger project that was submitted for ethical consideration to the Biomedical Research Ethics Committee of the University of KwaZulu-Natal in South Africa. This study's findings will be published in a peer-reviewed journal and provided to relevant stakeholders.

SYSTEMATIC REVIEW REGISTRATION

Open Science Framework (OSF): https://osf.io/ht8wr.

Report of the 2nd workshop of the International Collaboration on advanced vaccinology training

At a workshop on 22-24 March 2022, leaders of 33 advanced vaccinology courses were invited to meet with partners to further the aims of the International Collaboration on Advanced Vaccinology Training (ICAVT) initiated in 2018 to assist courses in addressing challenges in priority areas and facilitate interactions and exchange of information. This included: an update to the landscape analysis of advanced vaccinology courses conducted in 2018, sharing experiences and good practices in the implementation of virtual training, reviewing the training needs of target audiences, informing courses of the principles, challenges, and added value of accreditation, discussing course evaluations and measurement of course impact, reviewing principles and support needed for quality cascade training, reviewing COVID-19 impact on training and identifying remaining related training needs, and identifying solutions to facilitate refresher courses and ways to facilitate networking of courses' alumni (particularly for virtual courses). The aims were to identify needs and impediments and implement necessary actions to facilitate sharing of information and resources between courses, to identify need for further developments of the e-Portal of the Collaboration (icavt.org) established to facilitate communication between the different courses and assist future course participants identify the most suitable course for them, and to discuss the formalization of the Collaboration. During the workshop, participants looked at several reports of surveys completed by courses and courses' alumni or partners. The COVID-19 pandemic impacted the delivery of some vaccinology courses leading to postponement, delivery online or hybrid training events. Lack of sustainable funding remained a major constraint for advanced vaccinology training and needs to be addressed. The Collaboration was consolidated with responsibilities and benefits for the members better defined. There was strong support for the Collaboration to continue with the organization of educational sessions at future workshops. The meeting re-enforced the view that there was much enthusiasm and commitment for the Global Collaboration and its core values.

Advanced vaccinology training globally: Update and impact of the COVID-19 crisis

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A total of 33 advanced vaccinology courses were in existence in 2021.

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Some vaccinology courses were not sustained since 2018.

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The number of vaccinology courses has been increasing during the last few years, with courses offered in each WHO region.

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The COVID-19 pandemic resulted in the cancellation or postponement of some vaccinology courses.

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Due to the COVID-19 pandemic, an increased number of courses are using an online or hybrid format.

The rapid development of innovations and new technologies, the focus on the life-course approach to immunization and equity, and the prevalent hesitancy towards vaccines requires immunization staff to be well-trained and updated regularly in order to deliver quality immunization services to the public. The need for advanced vaccinology training is therefore paramount. In preparation for a second Global Workshop on Advanced Vaccinology Training that took place in March 2022, this paper presents the results of a survey aiming to provide a thorough update of a landscape analysis on advanced vaccinology courses conducted in 2018 and a look at the impact of the COVID-19 crisis. Thirty-three course organizers responded to a survey to provide information on their respective course. Of those, 17 courses are short courses, 11 post-graduate courses and 5 are Master level courses. Most courses are organized on an annual basis. Even though some courses were not sustained overtime, the number of courses has been increasing during the last few years, and at least one vaccinology course is now being offered in each WHO region. Although the training capacity has increased tremendously, the need still exceeds the capacity and many courses have way more applicants than they can select. The most frequent challenges reported included sustainable funding and identifying faculty. The COVID-19 pandemic impacted the delivery of several vaccinology courses, which have been postponed or reformatted to an online or hybrid training event. An e-portal of the global collaboration has been established to facilitate communication between the different courses and to assist future course participants to identify the most suitable course for their needs.

Oral organic nanovaccines against bacterial and viral diseases

Vaccines have saved millions of humans and animals from deadly diseases. Many vaccines are still under development to fight against lethal diseases. Indeed, subunit vaccines are a versatile approach with several advantageous attributes, but they lack strong immunogenicity. Nanotechnology is an avenue to vaccine development because nanoparticles may serve as nanocarriers and adjuvants, which are critical aspects for oral vaccines. This review provides an update of oral organic nanovaccines, describing suitable nanomaterials for oral vaccine design and recent (last five-year view) oral nanovaccine developments to fight against those principal pathogens causing human and animal diseases.

Acceptable Young Calf Vaccination Strategies-What, When, and How?

Vaccination is an important component for the prevention and control of disease in calves. Too often vaccines are viewed as a catch-all solution for management and nutrition errors; the "best" vaccine can never overcome these deficiencies. Proper vaccination in the young calf and developing heifer is the key to long-term development of a productive dairy cow. To actually immunize animals, animals must be able to respond to vaccines, which is dependent on the level of animal husbandry. Each vaccine program needs to be designed based on animal flow, actual "disease" threats, and labor on the farm.

[Human and animal health]

The concept of "one health" applies perfectly to human health and animal health because many diseases are zoonoses. There are many historical examples of effective collaboration between veterinary medicine and human medicine in the development of the first vaccines used in the world (smallpox, rabies, tetanus, diphtheria, tuberculosis, etc.). But when a new disease appears in animals, the risk of possible transmission to humans is difficult to estimate. In the latter case, the loss of consumer confidence in the face of scientific uncertainties can cause a health crisis (examples of bovine spongiform encephalopathy and H5N1 avian plague). But the most serious crisis that we have known since early 2020 is Covid-19 pandemic, which confirms that the modification of the ecosystems of certain wild species such as the horseshoe bats can have significant consequences for the public health. Animals infected with Covid-19 have been contaminated by humans but we cannot currently exclude an animal reservoir risk for SARS-CoV-2 which has circulated around the world.

Vaccination in the context of the COVID-19 pandemic

In this review, we described the history of vaccination, the different types of vaccines, and how vaccination coverage has been affected by the current COVID-19 pandemic. The effectiveness of the vaccines under metabolic host conditions is analyzed, especially when people have lost their immunocompetence, such as in patients with chronic kidney disease who are in dialysis treatment. Vaccines are produced in a variety of industrial methods, modifying costs. The novel field of vaccinomics includes the set of immune responses, the satisfactory levels of neutralizing antibodies, the production of metabolites, and the induction of protein expression. Finally, an analysis is made of the confusing messages regarding vaccination that are disseminated on social networks, and general recommendations are given.

Time and cost of administering COVID-19 mRNA vaccines in the United States

In early 2020, the World Health Organization (WHO) declared the coronavirus disease 2019 (COVID-19) outbreak a global pandemic. In response, two novel messenger RNA (mRNA)-based vaccines: mRNA-1273 (Moderna) and BNT162b2 (Pfizer-BioNTech) were rapidly developed. A thorough understanding of the differences in workflow requirements between the two vaccines may lead to improved efficiencies and reduced economic burden, both of which are crucial for streamlining vaccine deployment and minimizing wastage. Vaccine administration workflow costs are borne by providers and reimbursed separately from dose acquisition in the United States. Currently, mRNA-1273 and BNT162b2 are the most administered COVID-19 vaccines in the United States. In this study, US-licensed and practicing pharmacists were interviewed to collect data on differences in terms of labor costs associated with the workflows for mRNA-1273 and BNT162b2. Results suggest the cost differential for mRNA-1273 compared to BNT162b2 is -$0.82 (or -$1.01 when assuming volume equivalency). If extrapolated to even just a proportion of the remaining unvaccinated US population, this can amount to significant workflow efficiencies and lower vaccine administration costs. Further, as key differences in the vaccine workflow steps between the two vaccines would be similar in other settings/regions, these findings are likely transferable to health-care systems worldwide.

[Reverse vaccinology: strategy against emerging pathogens]

New technologies in vaccinology are capable of achieving fast development, as well as large-scale production of effective and safe vaccines. Reverse vaccinology is an in silico methodology, which studies different characteristics of infectious agents, in order to identify antigens that are good vaccine candidates, without the need of traditional culture. This strategy is based on bioinformatics tools, that in a simple, safety and inexpensive way, reduces time and effort significantly in the new vaccine design, against traditional vaccinology. In recent years, the rapid spread of infections by emerging pathogens requires prompt development of new vaccines. Bioinformatic strategies joined with the latest next-generation vaccines allow the selection of vaccine candidates in a short time, which is relevant in the development of new vaccines against pathogens with pandemic potential.

Secretome characterization of clinical isolates from the Mycobacterium abscessus complex provides insight into antigenic differences

BACKGROUND

Mycobacterium abscessus (MAB) is a widely disseminated pathogenic non-tuberculous mycobacterium (NTM). Like with the M. tuberculosis complex (MTBC), excreted / secreted (ES) proteins play an essential role for its virulence and survival inside the host. Here, we used a robust bioinformatics pipeline to predict the secretome of the M. abscessus ATCC 19977 reference strain and 15 clinical isolates belonging to all three MAB subspecies, M. abscessus subsp. abscessus, M. abscessus subsp. bolletii, and M. abscessus subsp. massiliense.

RESULTS

We found that ~ 18% of the proteins encoded in the MAB genomes were predicted as secreted and that the three MAB subspecies shared > 85% of the predicted secretomes. MAB isolates with a rough (R) colony morphotype showed larger predicted secretomes than isolates with a smooth (S) morphotype. Additionally, proteins exclusive to the secretomes of MAB R variants had higher antigenic densities than those exclusive to S variants, independent of the subspecies. For all investigated isolates, ES proteins had a significantly higher antigenic density than non-ES proteins. We identified 337 MAB ES proteins with homologues in previously investigated M. tuberculosis secretomes. Among these, 222 have previous experimental support of secretion, and some proteins showed homology with protein drug targets reported in the DrugBank database. The predicted MAB secretomes showed a higher abundance of proteins related to quorum-sensing and Mce domains as compared to MTBC indicating the importance of these pathways for MAB pathogenicity and virulence. Comparison of the predicted secretome of M. abscessus ATCC 19977 with the list of essential genes revealed that 99 secreted proteins corresponded to essential proteins required for in vitro growth.

CONCLUSIONS

This study represents the first systematic prediction and in silico characterization of the MAB secretome. Our study demonstrates that bioinformatics strategies can help to broadly explore mycobacterial secretomes including those of clinical isolates and to tailor subsequent, complex and time-consuming experimental approaches accordingly. This approach can support systematic investigation exploring candidate proteins for new vaccines and diagnostic markers to distinguish between colonization and infection. All predicted secretomes were deposited in the Secret-AAR web-server ( http://microbiomics.ibt.unam.mx/tools/aar/index.php ).

Measles-mumps-rubella vaccine at 6 months of age, immunology, and childhood morbidity in a high-income setting: study protocol for a randomized controlled trial

BACKGROUND

Measles is a highly contagious and serious infection. Before the introduction of vaccination, measles caused yearly epidemics putting vulnerable children at risk of brain damage and death. Despite safe and cost-effective vaccines, measles remains a leading cause of death in children globally. Due to insufficient vaccine coverage and low levels of in utero transferred antibodies from vaccinated mothers, outbreaks of measles in Denmark and other high-income countries are observed at increasing frequency. The current vaccine was introduced in Denmark in 1987 as a one-shot measles-mumps-rubella vaccine at 15 months, a timing chosen to avoid inhibition of the infant's immune response by maternal antibodies. One generation later, the MMR vaccinated mothers have lower antibody levels compared to the naturally infected, and their infants are already susceptible at 6 months of age or earlier, thus increasing the risk of epidemics.

METHODS

The Danish MMR trial is a double-blind randomized clinical trial recruiting between March 2019 and December 2021 with last patient last visit in February 2022. Altogether N = 6500 infants aged 6 months will be randomly assigned to intramuscular vaccination with routine MMR (M-M-R VaxPro) or placebo (solvent only). According to the Danish Childhood vaccination program, all infants will receive a routine MMR vaccination at 15 months of age. At randomization, 1 month later, and 1 month after routine MMR vaccination at 15 months of age, a blood sample is drawn from app. 10% (N = 600) of the population. Additionally, hair, saliva, and urine are sampled at randomization. The co-primary study outcomes are immunogenicity 1 month after MMR vaccination at 6 months of age assessed as plaque-reduction neutralization test, and incidence of infectious disease hospitalizations from randomization to 12 months of age. Six weeks post randomization, all participants are interviewed regarding adverse events.

TRIAL REGISTRATION

The trial is registered in the EU Clinical Trials Registry. EudraCT registration number: 2016-001901-18 . Registered on 14 February 2017.

Network vaccinology

The structure and function of the immune system is governed by complex networks of interactions between cells and molecular components. Vaccination perturbs these networks, triggering specific pathways to induce cellular and humoral immunity. Systems vaccinology studies have generated vast data sets describing the genes related to vaccination, motivating the use of new approaches to identify patterns within the data. Here, we describe a framework called Network Vaccinology to explore the structure and function of biological networks responsible for vaccine-induced immunity. We demonstrate how the principles of graph theory can be used to identify modules of genes, proteins, and metabolites that are associated with innate and adaptive immune responses. Network vaccinology can be used to assess specific and shared molecular mechanisms of different types of vaccines, adjuvants, and routes of administration to direct rational design of the next generation of vaccines.

[Practices and reflections on lecturing of vaccinology in general education towards undergraduate students: from the perspective of Comprehensive Health and New Medicine]

Multiple and cross disciplinary education among medical sciences and other subjects have been much emphasized in the context of new medicine, which generate higher standards of general medical education practice. The department of epidemiology, school of public health, Fudan university, offer lectures of vaccinology towards undergraduate students in general education. This article introduces the course objectives, content, selection of teaching materials, teaching methods as well as primary output since the Autumn semester in 2018. In addition, this article proposes ideas of course improvement in the context of responses to COVID-19　　　pandemic. The teaching exploration could provide reference for related universities on medical and public health education from the perspective of comprehensive health.

Advanced vaccinology education: Landscaping its growth and global footprint

In preparation for the first Global Vaccinology Training workshop in 2018, a survey of 27 advanced vaccinology courses was conducted to provide a landscape of the vaccinology education around the world. Advanced vaccinology courses have expanded dramatically over the last 20 years, with courses located in almost all regions, but with underrepresentation amongst the Eastern part of the European region, the Eastern Mediterranean and the Western Pacific regions. Most courses are of short duration (<2 weeks), have a global or regional reach, and attract a diverse range of participants from high, middle and low-income countries with representation from public health, academia, industry and less often regulators. Lack of sustainable funding and time commitments of faculty and coordinators is a constraint for most vaccinology courses and needs to be addressed. Continuation and extension of training in vaccinology worldwide will be necessary as increasing number of new and more complex vaccines are introduced, vaccine safety concerns and rumors continue their trend, and reemergence of some vaccine-preventable diseases will require a competent workforce to advance and deploy immunizations to larger populations.

Immunosenescence: A systems-level overview of immune cell biology and strategies for improving vaccine responses

Immunosenescence contributes to a decreased capacity of the immune system to respond effectively to infections or vaccines in the elderly. The full extent of the biological changes that lead to immunosenescence are unknown, but numerous cell types involved in innate and adaptive immunity exhibit altered phenotypes and function as a result of aging. These manifestations of immunosenescence at the cellular level are mediated by dysregulation at the genetic level, and changes throughout the immune system are, in turn, propagated by numerous cellular interactions. Environmental factors, such as nutrition, also exert significant influence on the immune system during aging. While the mechanisms that govern the onset of immunosenescence are complex, systems biology approaches allow for the identification of individual contributions from each component within the system as a whole. Although there is still much to learn regarding immunosenescence, systems-level studies of vaccine responses have been highly informative and will guide the development of new vaccine candidates, novel adjuvant formulations, and immunotherapeutic drugs to improve vaccine responses among the aging population.

Global vaccinology training: Report from an ADVAC workshop

At a workshop on 7-8 November 2018 the leaders of 26 advanced vaccinology courses met to carry out an extensive review of the existing courses worldwide, in order to identify education gaps and future needs and discuss potential collaboration. The main conclusions of the workshop concerned: opportunities for strengthening and expanding the global coverage of vaccinology training; evaluation of vaccinology courses; updating knowledge after the course; how to facilitate post-course 'cascade' training; developing and sharing best practices; the application of online and innovative approaches in adult education; and how to reduce costs and facilitate wider access to vaccinology training. The importance of collaboration and information exchange through networks of alumni and between courses was stressed. A web platform to provide information about existing courses for potential applicants is needed. Lack of sustainable funding is a constraint for vaccinology training and needs to be addressed.

Lessons for general vaccinology research from attempts to develop an HIV vaccine

In the past when large investments have been made in tackling narrow scientific challenges, the enormous expansion in our knowledge in one small area has had a spill-over effect on research and treatment of other diseases. The large investment in HIV vaccine development in recent years has the potential for such an effect on vaccine development for other diseases. HIV vaccine developers have experienced repeated failure using the standard approaches to vaccine development. This has forced them to consider immune responses in greater depth and detail. It has led to a recognition of the importance of epitopic specificity in both antibody and T cell responses. Also, it has led to an understanding of the importance of affinity maturation in antibody responses and the quality of T cell responses in T cell-mediated immunity. It has advanced the development of many novel vaccine vectors and vehicles that are now available for use in other vaccines. Further, it has focused attention on the impact of research funding mechanisms and community engagement on vaccine development. These developments and considerations have implications for vaccinology more generally. Some suggestions are made for investigators working on other "hard-to-develop" vaccines.

Immune parameters to p67C antigen adjuvanted with ISA206VG correlate with protection against East Coast fever

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Three doses of p67C antigen generated stronger immune responses than two doses.

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Antibody titers and CD4⁺ T-cell proliferation correlated with protection against ECF.

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The number of doses could not be reduced from three to two without compromising the protection.

East Coast fever (ECF) is a lymphoproliferative disease caused by the tick-transmitted protozoan parasite Theileria parva. ECF is one of the most serious cattle tick-borne diseases in Sub-Saharan Africa. We have previously demonstrated that three doses of the C-terminal part of the sporozoite protein p67 (p67C) adjuvanted with ISA206VG confers partial protection against ECF at a herd level. We have tested the efficacy of two doses of this experimental vaccine, as reducing the vaccination regimen would facilitate its deployment in the field. We reconfirm that three antigen doses gave a significant level of protection to severe disease (46%, ECF score < 6) when compared with the control group, while two doses did not (23%). Animals receiving three doses of p67C developed higher antibody titers and CD4⁺ T-cell proliferation indices, than those which received two doses. A new panel of immune parameters were tested in order to identify factors correlating with protection: CD4⁺ proliferation index, total IgG, IgG1, IgG2 and IgM half maximal titers and neutralization capacity of the sera with and without complement. We show that some of the cellular and humoral immune responses provide preliminary correlates of protection.

HPV vaccine confidence and cases of mass psychogenic illness following immunization in Carmen de Bolivar, Colombia

We report the case of multiple adverse reactions following HPV vaccination in Colombian adolescents in Carmen de Bolivar. In August 2012, the country introduced a school-based HPV immunization programme which successfully reached over 90% of the target population in the first year. In 2014, between May 29th and June 2nd,15 adolescent girls in one school presented adverse reactions after vaccination and were admitted to the local hospital. Soon, videos of girls fainting, twitching, and arriving unconscious at emergency rooms started to appear in national news media as well as on social media platforms such as YouTube. The viral spread of these videos and disturbing images were followed by the viral spread of symptoms, with over 600 cases reported across Colombia. Thorough epidemiological investigation by Colombian health authorities found no organic association between the teenagers' symptoms and the HPV vaccine, concluding this was a case of mass psychogenic reaction to vaccination. Scientific evidence did not appease the anxious public whose confidence in HPV immunization dropped dramatically. By 2016, HPV vaccine uptake among eligible girls declined to 14% for the first dose and 5% for the complete course, down from 98% and 88%, respectively, in 2012. We document this case and discuss the role of news and social media, particularly YouTube, as a driver of contagious psychogenic reactions. We also discuss the role of health authorities and government, and the importance of acting rapidly and appropriately to contain the spread of such symptoms and maintain public confidence in vaccines.

Systems analysis of human vaccine adjuvants

The discovery and wide spread use of vaccines have saved millions of lives in the past few decades. Vaccine adjuvants represent an integral part of the modern vaccines. Despite numerous efforts, however, only a handful of vaccine adjuvants is currently available for human use. A comprehensive understanding of the mechanisms of action of adjuvants is pivotal to harness the potential of existing and new adjuvants in mounting desirable immune responses to counter human pathogens. Decomposing the host response to vaccines and its components at systems level has recently been made possible owing to the recent advancements in Omics technology and cutting edge immunological assays powered by systems biology approaches. This approach has begun to shed light on the molecular signatures of several human vaccines and adjuvants. This review is an attempt to provide an overview of the recent efforts in systems analysis of vaccine adjuvants that are currently in clinic.

Public policy for meningococcal vaccination

On an individual basis, meningococcal disease is consistently shown to be one of the most feared potential childhood infections. On a population level, any clustering of cases or increase in disease requires proactive health protection management, while epidemics can be devastating. It is therefore no surprise that developing protective meningococcal vaccines and effective strategies for their implementation has been a continuing public health priority for some decades.

Continuing global improvement in human papillomavirus DNA genotyping services: The 2013 and 2014 HPV LabNet international proficiency studies

BACKGROUND

Accurate and internationally comparable human papillomavirus (HPV) DNA detection and typing services are essential for HPV vaccine research and surveillance.

OBJECTIVES

This study assessed the proficiency of different HPV typing services offered routinely in laboratories worldwide.

STUDY DESIGN

The HPV Laboratory Network (LabNet) has designed international proficiency panels that can be regularly issued. The HPV genotyping proficiency panels of 2013 and 2014 contained 43 and 41 coded samples, respectively, composed of purified plasmids of sixteen HPV types (HPV 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68a and 68b) and 3 extraction controls. Proficient typing was defined as detection in both single and multiple infections of 50 International Units of HPV 16 and HPV 18 and 500 genome equivalents for the other 14 HPV types, with at least 97% specificity.

RESULTS

Ninety-six laboratories submitted 136 datasets in 2013 and 121 laboratories submitted 148 datasets in 2014. Thirty-four different HPV genotyping assays were used, notably Linear Array, HPV Direct Flow-chip, GenoFlow HPV array, Anyplex HPV 28, Inno-LiPa, and PGMY-CHUV assays. A trend towards increased sensitivity and specificity was observed. In 2013, 59 data sets (44%) were 100% proficient compared to 86 data sets (59%) in 2014. This is a definite improvement compared to the first proficiency panel, issued in 2008, when only 19 data sets (26%) were fully proficient.

CONCLUSION

The regularly issued global proficiency program has documented an ongoing worldwide improvement in comparability and reliability of HPV genotyping services.

Whither vaccines?

Currently used vaccines have had major effects on eliminating common infections, largely by duplicating the immune responses induced by natural infections. Now vaccinology faces more complex problems, such as waning antibody, immunosenescence, evasion of immunity by the pathogen, deviation of immunity by the microbiome, induction of inhibitory responses, and complexity of the antigens required for protection. Fortunately, vaccine development is now incorporating knowledge from immunology, structural biology, systems biology and synthetic chemistry to meet these challenges. In addition, international organisations are developing new funding and licensing pathways for vaccines aimed at pathogens with epidemic potential that emerge from tropical areas.

A reverse vaccinology approach to the identification and characterization of Ctenocephalides felis candidate protective antigens for the control of cat flea infestations

Background

Despite the abundance of the domestic cat flea, Ctenocephalides felis (Bouché, 1835) and disease risks associated with them, flea control is difficult and requires the development of new control interventions such as vaccines. In this study, a reverse vaccinology approach was designed to achieve a rational selection of cat flea candidate protective antigens.

Methods

Based on transcriptomics and proteomics data from unfed adult fleas it was possible to select more specific candidate protective antigens based on highly represented and functionally relevant proteins present in the predicted exoproteome. The protective capacity of the recombinant antigens was evaluated for the control of C. felis infestations in vaccinated cats.

Results

Vaccination with recombinant antigens induced an antibody response in immunized cats. Furthermore, a correlation was obtained between the effect of vaccination (antibody levels) and vaccine efficacy on flea phenotype (egg hatchability). The results suggested that the main effect of vaccination with these antigens was on reducing cat flea egg hatchability and fertility, with an overall vaccine efficacy of 32–46%. Although vaccination with these antigens did not have an effect on flea infestations, vaccines affecting reproductive capacity could reduce cat flea populations, particularly under conditions of direct insect transmission between cats.

Conclusions

These results support the development of vaccines with protective antigens affecting flea reproduction and development after feeding on immunized animals for the control of cat flea infestations.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-2618-x) contains supplementary material, which is available to authorized users.

Heparin removal by ecteola-cellulose pre-treatment enables the use of plasma samples for accurate measurement of anti-Yellow fever virus neutralizing antibodies

Technological innovations in vaccinology have recently contributed to bring about novel insights for the vaccine-induced immune response. While the current protocols that use peripheral blood samples may provide abundant data, a range of distinct components of whole blood samples are required and the different anticoagulant systems employed may impair some properties of the biological sample and interfere with functional assays. Although the interference of heparin in functional assays for viral neutralizing antibodies such as the functional plaque-reduction neutralization test (PRNT), considered the gold-standard method to assess and monitor the protective immunity induced by the Yellow fever virus (YFV) vaccine, has been well characterized, the development of pre-analytical treatments is still required for the establishment of optimized protocols. The present study intended to optimize and evaluate the performance of pre-analytical treatment of heparin-collected blood samples with ecteola-cellulose (ECT) to provide accurate measurement of anti-YFV neutralizing antibodies, by PRNT. The study was designed in three steps, including: I. Problem statement; II. Pre-analytical steps; III. Analytical steps. Data confirmed the interference of heparin on PRNT reactivity in a dose-responsive fashion. Distinct sets of conditions for ECT pre-treatment were tested to optimize the heparin removal. The optimized protocol was pre-validated to determine the effectiveness of heparin plasma:ECT treatment to restore the PRNT titers as compared to serum samples. The validation and comparative performance was carried out by using a large range of serum vs heparin plasma:ECT 1:2 paired samples obtained from unvaccinated and 17DD-YFV primary vaccinated subjects. Altogether, the findings support the use of heparin plasma:ECT samples for accurate measurement of anti-YFV neutralizing antibodies.

Immunizations

Vaccinations are a cornerstone of the pretravel consultation. The pretravel provider should assess a traveler's past medical history, planned itinerary, activities, mode of travel, and duration of stay and make appropriate vaccine recommendations. Given that domestic vaccine-preventable illnesses are more common in international travelers than are exotic or low-income nation-associated vaccine-preventable illnesses, clinicians should first ensure that travelers are current regarding routine immunizations. Additional immunizations may be indicated in some travelers. Familiarity with geographic distribution and seasonality of infectious diseases is essential. Clinicians should be cognizant of which vaccines are live, as there exist contraindications for live vaccines.

Proteomic contributions to our understanding of vaccine and immune responses

Vaccines are one of the greatest public health successes; yet, due to the empirical nature of vaccine design, we have an incomplete understanding of how the genes and proteins induced by vaccines contribute to the development of both protective innate and adaptive immune responses. While the advent of genomics has enabled new vaccine development and facilitated understanding of the immune response, proteomics identifies potentially new vaccine antigens with increasing speed and sensitivity. In addition, as proteomics is complementary to transcriptomic approaches, a combination of both approaches provides a more comprehensive view of the immune response after vaccination via systems vaccinology. This review details the advances that proteomic strategies have made in vaccine development and reviews how proteomics contributes to the development of a more complete understanding of human vaccines and immune responses.

[Development of new vaccines]

Recent and important advances in the fields of immunology, genomics, functional genomics, immunogenetics, immunogenomics, bioinformatics, microbiology, genetic engineering, systems biology, synthetic biochemistry, proteomics, metabolomics and nanotechnology, among others, have led to new approaches in the development of vaccines. The better identification of ideal epitopes, the strengthening of the immune response due to new adjuvants, and the search of new routes of vaccine administration, are good examples of advances that are already a reality and that will favour the development of more vaccines, their use in indicated population groups, or its production at a lower cost. There are currently more than 130 vaccines are under development against the more wished (malaria or HIV), difficult to get (CMV or RSV), severe re-emerging (Dengue or Ebola), increasing importance (Chagas disease or Leishmania), and nosocomial emerging (Clostridium difficile or Staphylococcus aureus) infectious diseases.

New approaches to understanding the immune response to vaccination and infection

The immune system is a network of specialized cell types and tissues that communicates via cytokines and direct contact, to orchestrate specific types of defensive responses. Until recently, we could only study immune responses in a piecemeal, highly focused fashion, on major components like antibodies to the pathogen. But recent advances in technology and in our understanding of the many components of the system, innate and adaptive, have made possible a broader approach, where both the multiple responding cells and cytokines in the blood are measured. This systems immunology approach to a vaccine response or an infection gives us a more holistic picture of the different parts of the immune system that are mobilized and should allow us a much better understanding of the pathways and mechanisms of such responses, as well as to predict vaccine efficacy in different populations well in advance of efficacy studies. Here we summarize the different technologies and methods and discuss how they can inform us about the differences between diseases and vaccines, and how they can greatly accelerate vaccine development.

Malaria Vaccines: Moving Forward After Encouraging First Steps

An effective malaria vaccine that reduces morbidity and mortality and contributes to malaria elimination is a much-needed tool, particularly in endemic areas where health-care delivery and vector control efforts are difficult to sustain. RTS,S/AS01 is likely to be the first licensed malaria vaccine and represents an important step toward malaria control and elimination. However, a partially effective vaccine such as RTS,S/AS01 poses challenges for evaluating the efficacy of second-generation malaria vaccines. Whole-sporozoite immunization approaches have shown promising results, inducing sterile immunity in small-scale trials of malaria-naïve adults, but may not achieve durable sterile protection in endemic populations. Vaccines targeting both the pre-erythrocytic and the erythrocyte-invasive form of the parasite (merozoites) may abrogate breakthrough infections by neutralizing merozoites emerging from infected hepatocytes, whereas vaccines targeting the sexual stages seek to break the transmission cycle. Moving forward, a multi-stage vaccine could be the next step toward malaria elimination and eradication.

The history of the United States Advisory Committee on Immunization Practices (ACIP)

The United States Advisory Committee on Immunization Practices (ACIP) is a federal advisory committee that develops written recommendations for use of vaccines licensed by the Food and Drug Administration (FDA) for the U.S. civilian population. Vaccine development and disease outbreaks contributed to the need for a systematized, science-based, formal mechanism for establishing national immunization policy in this country. Formed in 1964, the ACIP was charged with this role. The committee has undergone significant changes in structure and operational activities during its 50-year history. The ACIP works closely with many liaison organizations to develop its immunization recommendations, which are harmonized among key professional medical societies. ACIP vaccine recommendations form two immunization schedules, which are updated annually: (1) the childhood and adolescent immunization schedule and (2) the adult immunization schedule. Today, once ACIP recommendations are adopted by the Director of the Centers for Disease Control and Prevention and the Secretary of the Department of Health and Human Services, these recommendations are published in Morbidity and Mortality Weekly Report (MMWR), become official policy, and are incorporated into the appropriate immunization schedule.

Host and Viral Factors in Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) is a major worldwide pathogen for which there is still no effective vaccine or antiviral treatment available, and immunoprophylaxis with RSV-specific antibodies (e.g., palivizumab) is used in limited clinical settings. In this review, we discuss virus-host interactions relevant to RSV pathobiology and how advances in cell and systems biology have accelerated knowledge in this area. We also highlight recent advances in understanding the relationship between RSV bronchiolitis and sequelae of recurrent wheezing and asthma, new findings into an intriguing interaction between RSV and air pollution, and exciting developments toward the goal of realizing a safe and effective RSV vaccine.

Vaccines today, vaccines tomorrow: a perspective

Vaccines are considered as one of the major contributions of the 20th century and one of the most cost effective public health interventions. The International Vaccine Institute has as a mission to discover, develop and deliver new and improved vaccines against infectious diseases that affects developing nations. If Louis Pasteur is known across the globe, vaccinologists like Maurice Hilleman, Jonas Salk and Charles Mérieux are known among experts only despite their contribution to global health. Thanks to a vaccine, smallpox has been eradicated, polio has nearly disappeared, Haemophilus influenzae B, measles and more recently meningitis A are controlled in many countries. While a malaria vaccine is undergoing phase 3, International Vaccine Institute, in collaboration with an Indian manufacturer has brought an oral inactivated cholera vaccine to pre-qualification. The field of vaccinology has undergone major changes thanks to philanthropists such as Bill and Melinda Gates, initiatives like the Decade of Vaccines and public private partnerships. Current researches on vaccines have more challenging targets like the dengue viruses, malaria, human immunodeficiency virus, the respiratory syncytial virus and nosocomial diseases. Exciting research is taking place on new adjuvants, nanoparticles, virus like particles and new route of administration. An overcrowded infant immunization program, anti-vaccine groups, immunizing a growing number of elderlies and delivering vaccines to difficult places are among challenges faced by vaccinologists and global health experts.