A short history of vaccination

Exploring Parental Attitudes and Perceptions Regarding Childhood Vaccinations in Greece: A Study Within the Framework of the National Health Examination Survey (EMENO)

AIM

Vaccinations have reduced illnesses and mortality rates globally, yet negative attitudes and uncertainty about them hinder their acceptability and efficacy. The study aims to document Greek parents' immunization perceptions and risk factors.

METHODS

Spanning 2014-2017, 447 parents (68% mothers) who participated in the Greek Health Examination Survey EMENO (National Survey of Morbidity and Risk Factors) completed an interview-delivered questionnaire. Attitudes were categorized into three groups: absolutely positive, positive, and negative. Absolutely positive attitudes included positive responses to all five statements in favor of vaccination and negative responses to the two statements against vaccination. Negative attitudes included positive responses to either one or both statements against vaccination and negative responses to all five statements in favor of vaccination.. All other participants were categorized as having a positive attitude. Skepticism towards vaccinations was classified into skeptical and non-skeptical groups based on responses to five statements implying uncertainty or skepticism. Participants were considered skeptical if they provided positive responses to at least three of these statements, and non-skeptical if they had none or up to two positive responses. The statistical analysis accounted for the study design whereas inverse probability weighting was used to adjust for non-response and multiple imputations were employed to impute missing values. The components of parental attitude and vaccine skepticism were identified using weighted multinomial logistic regression and logistic regression, respectively.

RESULTS

In total, 16.6% were classified as having absolutely positive attitudes towards vaccinations whereas 42.1% were skeptical of vaccines. Of all participants, 96.0% agreed that vaccinations are essential for their child's well-being and adhere to scientific recommendations. However, concerns were also mentioned, with 26.2% worrying about potential adverse effects, and 21.6% believing it is better to acquire immunity through illness rather than vaccination. Positive participants, compared to absolutely positive ones, were more likely to be of Greek origin (adjusted relative rate ratio (aRRR): 3.35; 95% CI: 1.53-7.30) and living in semi-urban areas (aRRR: 4.84; 95% CI: 1.77-13.29). Negative participants, in contrast, were more likely to have higher education (aRRR: 2.98; 95% CI: 1.05-8.44) but also to live in semi-urban areas (aRRR: 6.43; 95% CI: 1.69-24.56). Furthermore, parents of Greek origin had significantly higher odds of being skeptical towards vaccination (adjusted Odds Ratio (aOR): 2.86; 95% CI: 1.36-5.98), while married or cohabiting parents had lower odds of being skeptical compared to single parents (aOR: 0.60; 95% CI: 0.35-1.06).

CONCLUSIONS

While parents in this study recognize the importance of childhood immunizations, there is a widespread presence of negative attitudes and skepticism that can have a detrimental impact on vaccination rates.

Benefits of Combining Molecular Biology and Controlled Human Infection Model Methodologies in Advancing Vaccine Development

Infectious diseases continue to account for a significant portion of global deaths despite the use of vaccines for several centuries. Immunization programs around the world are a testament to the great success of multiple vaccines, yet there are still diseases without vaccines and others that require safer more effective ones. Addressing uncontrolled and emerging disease threats is restrained by the limitations and bottlenecks encountered with traditional vaccine development paradigms. Recent advances in modern molecular biology technologies have enhanced the interrogation of host pathogen interaction and deciphered complex pathways, thereby uncovering the myriad interplay of biological events that generate immune protection against foreign agents. Consequent to insights into the immune system, modern biology has been instrumental in the development and production of next generation 21st century vaccines. As these biological tools, commonly and collectively referred to as 'omics, became readily available, there has been a renewed consideration of Controlled Human Infection Models (CHIMs). Successful and reproducible CHIMs can complement modern molecular biology for the study of infectious diseases and development of effective vaccines in a regulated process that mitigates risk, cost, and time, with capacity to discern immune correlates of protection.

Childhood Immunization and Competing Mortality Risks in Kenya: A Longitudinal Analysis for Multiparous Mothers

OBJECTIVE

To assess the relationship between childhood immunization and mortality risks for nonvaccine-preventable diseases (competing mortality risks, or CMR) in Kenya.

STUDY DESIGN

A combination of the Global Burden of Disease and Demographic Health Survey data was used to measure basic vaccination status, CMR, and control variables for each child in the Demographic Health Survey data. A longitudinal analysis was performed. This uses within-mother variation between children to compare the vaccine decisions for different children, who are exposed to different mortality risks. The analysis also distinguishes between overall and disease-specific risks.

RESULTS

The study included 15 881 children born between 2009 and 2013, who were at least 12 months old at the time of interview and not part of a twin birth. Mean basic vaccination rates ranged from 27.1% to 90.2% and mean CMR from 13.00 to 738.32 deaths per 100 000 across different counties. A one-unit increase in mortality risk from diarrhea, the most prevalent disease among children in Kenya, is associated with a 1.1 percentage point decline in basic vaccination status. In contrast, mortality risks for other diseases and HIV increase the likelihood of vaccination. The effect of CMR was found to be stronger for children with higher birth orders.

CONCLUSIONS

A significant negative correlation between severe CMR and vaccination status was found, which has important implications for immunization policies, particularly in Kenya. Interventions aimed at reducing the most severe CMR, such as diarrhea, and targeted toward multiparous mothers may improve childhood immunization coverage.

Waning of maternal antibody against measles virus in Shufu, China

BACKGROUND

As measles vaccination coverage has increased, measles infection has shifted to the population of infants. We conducted a follow-up seroepidemiological study among mothers and their infants to evaluate measles seroprevalence and the persistence of maternal measles antibody in Shufu, Kashgar from 2018 to 2020.

METHODS

Maternal venous blood and cord blood was obtained among mothers and their infants at 0, 3, 5, 8, 9, and 12 months of age. An enzyme-linked immunosorbent assay was used for quantitative measurement of measles antibodies. We analyzed the correlation between maternal and neonatal measles antibodies, and antibodies persistence after infants were born.

RESULTS

The overall neonatal maternal ratio was 2.38 (95%CI: 2.05-2.71). The measles antibodies for mothers and newborns were 438.93 IU/mL (95%CI: 409.47-470.51 IU/mL) and 440.10 IU/mL (95%CI: 410.82-471.48 IU/mL), respectively. Neonatal measles antibodies were dropping after birth and then beginning to increase starting at 8 months of age.

CONCLUSIONS

Infant measles antibody levels progressively declined after birth regardless of maternal measles antibody levels. Efforts should be carried out to eliminate measles.

Harnessing the Immune Response to Fungal Pathogens for Vaccine Development

Invasive fungal infections are emerging diseases that kill over 1.5 million people per year worldwide. With the increase of immunocompromised populations, the incidence of invasive fungal infections is expected to continue to rise. Vaccines for viral and bacterial infectious diseases have had a transformative impact on human health worldwide. However, no fungal vaccines are currently in clinical use. Recently, interest in fungal vaccines has grown significantly. One Candida vaccine has completed phase 2 clinical trials, and research on vaccines against coccidioidomycosis continues to advance. Additionally, multiple groups have discovered various Cryptococcus mutant strains that promote protective responses to subsequent challenge in mouse models. There has also been progress in antibody-mediated fungal vaccines. In this review, we highlight recent fungal vaccine research progress, outline the wealth of data generated, and summarize current research for both fungal biology and immunology studies relevant to fungal vaccine development. We also review technological advancements in vaccine development and highlight the future prospects of a human vaccine against invasive fungal infections.

[Vaccination, a public health tool]

Vaccination remains a major public health tool, the only one that has enabled the eradication of an infectious disease, smallpox. In this fight, biotechnological innovations point to considerable progress in the development of new vaccines. However, whatever technical progress is made, the impact of a vaccination program will depend on its performance and on the support of the population.

Vaccines Against Antimicrobial Resistance

In the last century, life expectancy has increased considerably, thanks to the introduction of antibiotics, hygiene and vaccines that have contributed to the cure and prevention of many infectious diseases. The era of antimicrobial therapy started in the nineteenth century with the identification of chemical compounds with antimicrobial properties. However, immediately after the introduction of these novel drugs, microorganisms started to become resistant through different strategies. Although resistance mechanisms were already present before antibiotic introduction, their large-scale use and mis-use have increased the number of resistant microorganisms. Rapid spreading of mobile elements by horizontal gene transfer such as plasmids and integrative conjugative elements (ICE) carrying multiple resistance genes has dramatically increased the worldwide prevalence of relevant multi drug-resistant human pathogens such as Staphylococcus aureus, Neisseria gonorrhoeae, and Enterobacteriaceae. Today, antimicrobial resistance (AMR) remains one of the major global concerns to be addressed and only global efforts could help in finding a solution. In terms of magnitude the economic impact of AMR is estimated to be comparable to that of climate global change in 2030. Although antibiotics continue to be essential to treat such infections, non-antibiotic therapies will play an important role in limiting the increase of antibiotic resistant microorganisms. Among non-antibiotic strategies, vaccines and therapeutic monoclonal antibodies (mAbs) play a strategic role. In this review, we will summarize the evolution and the mechanisms of antibiotic resistance, and the impact of AMR on life expectancy and economics.

The cellular and humoral immune response to influenza vaccination is comparable in asthmatic and healthy subjects

Annual influenza vaccination is recommended as a preventive measure for all patients with asthma since asthma exacerbations in children and adults are associated to viral infections including influenza. There is concern about the adequate immune response in asthmatics with ICS treatment. The production of antibodies to influenza in asthmatics has been demonstrated. However, cellular immunity is poorly understood. The aim of the study was to compare the humoral and cellular immune responses to influenza vaccine in asthmatic and healthy subjects. Twenty-five asthmatic patients attending the Allergy and Clinical Immunology Service at the Hospital General de Mexico and 25 healthy adults were included. Blood samples were obtained before, 4 and 12 months after immunization with influenza vaccine, influenza-specific antibodies were determined by the hemagglutination inhibition test and influenza-specific memory B, TCD4+, and TCD8 + lymphocytes were determined by flow cytometry. All the asthmatic patients received ICS treatment. The Geometric Mean titers for all influenza serotypes were similar in both groups; seropositivity and the cellular immune response increased in both groups over time and was comparable. Influenza vaccination in asthmatic patients with immunotherapy and ICS achieved protective antibody levels and cellular immunity over time comparable to healthy subjects.

Active surveillance of adverse events following immunization (AEFI): a prospective 3-year vaccine safety study

BACKGROUND

Vaccines used in national immunization programs are considered safe and effective but immunization safety has become as important as the efficacy of vaccination programs. The objective of the study was to detect adverse events following immunization (AEFIs) to all vaccines administered to a pediatric population in India.

METHODS

The prospective active vaccine safety surveillance study enrolled eligible children in the age group 0-5 years receiving vaccination from the immunization center at JSS Hospital, Mysuru. Study participants were monitored at the site for 30 min following vaccination and a telephonic survey was made after 8 days to identify all AEFIs. Causality assessment of the AEFIs were done using a new algorithm developed by the safety and vigilance department of the World Health Organization.

RESULTS

The incidence of reported AEFIs was 13.7%. The most frequently reported AEFI was fever (n = 3095, 93.2%) with an incidence of 109.7 per 1000 doses of vaccine administered, followed by persistent crying (n = 69, 2.4 per 1000 doses of vaccine) and diarrhea (n = 57, 2.0 per 1000 doses of vaccine). The majorly implicated vaccine for AEFIs was Pentavac® followed by BCG. Consistent causal association to immunization was observed in 93.4% of cases.

CONCLUSIONS

A high incidence rate of AEFI was observed in our study population when compared with previous published studies. AEFI surveillance studies help to detect changes in the frequency of adverse events, which may be an alert to consider vaccine quality or identify a specific risk among the local population.

Kingdon's Multiple Streams Framework and the Analysis of Decision-Making Processes Regarding Publicly-Funded Immunization Programs

Introduction: The implementation of a publicly-funded immunization program results from a complex decision-making process. John Kingdon's 'Multiple Streams Framework' has been extensively used to analyze how and why governmental policies were adopted. Area covered: Ideas that will ultimately end up in a proposal for a new immunization program develop gradually along three main streams: (i) the problem stream, which focuses on a particular vaccine-preventable disease and its perception by stakeholders; (ii) the policy stream, which is centered on experts' views on the optimal use of available vaccines; and (iii) the politics stream, which consists of socio-political factors, including budgetary constraints. Ideas are progressively shaped by policy entrepreneurs into a proposal with concrete implementation strategies. The three streams then converge within a policy window, during which adoption is especially likely to occur. To survive, the proposed program should be operationally feasible, consistent with mainstream social values, and financially affordable. The timing of the policy window is usually unpredictable and of short duration. Expert opinion: Analytical frameworks traditionally used to assess immunization programs focus on the technical aspects of the disease, the vaccine, and the program. The 'Multiple Streams Framework' brings added analytical value by enlarging the scope of the analysis into the political arena.

Safety and immunogenicity of VAQTA® in children 12-to-23 months of age with and without administration of other US pediatric vaccines

Safety and immunogenicity data from 5 clinical trials conducted in the US in children 12-to-23 months old where HAVi was administered alone or concomitantly with other pediatric vaccines (M-M-R®II, Varivax®, TRIPEDIA®, Prevnar®, ProQuad®, PedvaxHIB®, and INFANRIX®) were combined. Among 4,374 participants receiving ≥ 1 dose of HAVi, 4,222 (97%) had safety follow-up and the proportions reporting adverse events (AE) were comparable when administered alone (69.4%) or concomitantly with other pediatric vaccines (71.1%). The most common solicited injection-site AEs were pain/tenderness (Postdose 1: 25.8%; Postdose 2: 26.1%) and redness (Postdose 1: 13.6%; Postdose 2: 15.1%). The most common vaccine-related systemic AEs were fever (≥ 100.4ºF, 12.2%) and irritability (8.1%). Serious AEs (SAEs) were observed at a rate of 0.4%; 0.1% were considered vaccine-related. No deaths were reported within 14 days following a dose of HAVi. These integrated analyses also showed that protective antibody concentrations were elicited in 100% of toddlers after two doses and 92% after a single dose, regardless of whether HAVi was given concomitantly with other vaccines or alone. These results demonstrate that HAVi was well-tolerated whether given alone or concomitantly with other vaccines, with a low incidence of vaccine-related SAEs. HAVi was immunogenic in this age group regardless of whether administered with or without other pediatric vaccines and whether 1 or 2 doses were administered. HAVi did not impact the immune response to other vaccines. These data continue to support the routine use of HAVi with other pediatric vaccines in children ≥ 12 months of age.

Who's the Target: Mother or Baby?

Maternal immunization for prevention of morbidity and mortality of pregnant women and their neonates due to infectious diseases is ongoing worldwide. The complexity of vaccine research and development in this population is challenging. Not only do vaccines for pregnant women require evidence of immunogenicity, potency, stability, and limited reactogenicity, they must also provide efficacy in decreasing morbidity for the pregnant woman, her fetus, and the neonate, demonstrate safety or lack of evidence of harm, and offer benefit or potential benefit of vaccination during pregnancy. Since the 19th century, evidence of protective effects of vaccination during pregnancy has been documented. Pandemic influenza and pertussis outbreaks in recent years have affected a paradigm shift in vaccine research and development as well as current policy regarding immunization in pregnancy. Studies of the immune system in pregnant women and neonates have shown that immune changes associated with pregnancy in women do not interfere with maternal vaccine responses, multiple factors are important in transplacental transfer of antibodies, and maternal antibodies are beneficial to neonates. In recent years, guidelines have been developed by expert panels to help design studies for maternal vaccinations and for harmonization of data collection, analysis, and adverse event reporting. Further research into maternal and neonatal immunology, transplacental antibody transfer, and epidemiology of diseases is needed, especially as new vaccines to respiratory syncytial virus, cytomegalovirus, and Group B streptococcus are developed. Maternal vaccinations have the potential to change the epidemiology of infectious diseases in reproductive health and pediatrics and may lead to new clinical applications to improve global maternal and neonatal health.

Policy making for vaccine use as a driver of vaccine innovation and development in the developed world

In the past 200years, vaccines have had unmistakable impacts on public health including declines in morbidity and mortality, most markedly in economically-developed countries. Highly engineered vaccines including vaccines for conditions other than infectious diseases are expected to dominate future vaccine development. We examine immunization vaccine policy as a driver of vaccine innovation and development. The pathways to recommendation for use of licensed vaccines in the US, UK, Canada and Australia have been similar, including: expert review of disease epidemiology, disease burden and severity; vaccine immunogenicity, efficacy and safety; programmatic feasibility; public demand; and increasingly cost-effectiveness. Other attributes particularly important in development of future vaccines are likely to include: duration of immunity for improved vaccines such as pertussis; a greater emphasis on optimizing community protection rather than direct protection only; programmatic implementation, feasibility, improvements (as in the case of development of a universal influenza vaccine); public concerns/confidence/fears related to outbreak pathogens like Ebola and Zika virus; and major societal burden for combating hard to treat diseases like HIV and antimicrobial resistant pathogens. Driving innovation and production of future vaccines faces enormous economic hurdles as available approaches, technologies and regulatory pathways become more complex. As such, cost-mitigating strategies and focused, aligned efforts (by governments, private organizations, and private-public partnerships) will likely be needed to continue to spur major advances in vaccine technologies and development.

The use of databases, data mining and immunoinformatics in vaccinology: where are we?

INTRODUCTION

Vaccinology has evolved from a sub-discipline focussed on simplistic vaccine development based on antibody-mediated protection to a separate discipline involving epidemiology, host and pathogen biology, immunology, genomics, proteomics, structure biology, protein engineering, chemical biology, and delivery systems. Data mining in combination with bioinformatics has provided a scaffold linking all these disciplines to the design of vaccines and vaccine adjuvants. Areas covered: This review provides background knowledge on immunological aspects which have been exploited with informatics for the in silico analysis of immune responses and the design of vaccine antigens. Furthermore, the article presents various databases and bioinformatics tools, and discusses B and T cell epitope predictions, antigen design, adjuvant research and systems immunology, highlighting some important examples, and challenges for the future. Expert opinion: Informatics and data mining have not only reduced the time required for experimental immunology, but also contributed to the identification and design of novel vaccine candidates and the determination of biomarkers and pathways of vaccine response. However, more experimental data is required for benchmarking immunoinformatic tools. Nevertheless, developments in immunoinformatics and reverse vaccinology, which are nascent fields, are likely to hasten vaccine discovery, although the path to regulatory approval is likely to remain a necessary impediment.

Vero cell technology for rapid development of inactivated whole virus vaccines for emerging viral diseases

INTRODUCTION

Rapid development and production of vaccines against emerging diseases requires well established, validated, robust technologies to allow industrial scale production and accelerated licensure of products. Areas covered: A versatile Vero cell platform has been developed and utilized to deliver a wide range of candidate and licensed vaccines against emerging viral diseases. This platform builds on the 35 years' experience and safety record with inactivated whole virus vaccines such as polio vaccine. The current platform has been optimized to include a novel double inactivation procedure in order to ensure a highly robust inactivation procedure for novel emerging viruses. The utility of this platform in rapidly developing inactivated whole virus vaccines against pandemic (-like) influenza viruses and other emerging viruses such as West Nile, Chikungunya, Ross River and SARS is reviewed. The potential of the platform for development of vaccines against other emerging viruses such as Zika virus is described. Expert commentary: Use of this platform can substantially accelerate process development and facilitate licensure because of the substantial existing data set available for the cell matrix. However, programs to provide vaccines against emerging diseases must allow alternative clinical development paths to licensure, without the requirement to carry out large scale field efficacy studies.

Yeast lysates carrying the nucleoprotein from measles virus vaccine as a novel subunit vaccine platform to deliver Plasmodium circumsporozoite antigen

Background

Yeast cells represent an established bioreactor to produce recombinant proteins for subunit vaccine development. In addition, delivery of vaccine antigens directly within heat-inactivated yeast cells is attractive due to the adjuvancy provided by the yeast cell. In this study, Pichia pastoris yeast lysates carrying the nucleoprotein (N) from the measles vaccine virus were evaluated as a novel subunit vaccine platform to deliver the circumsporozoite surface antigen (CS) of Plasmodium. When expressed in Pichia pastoris yeast, the N protein auto-assembles into highly multimeric ribonucleoparticles (RNPs). The CS antigen from Plasmodium berghei (PbCS) was expressed in Pichia pastoris yeast in fusion with N, generating recombinant PbCS-carrying RNPs in the cytoplasm of yeast cells.

Results

When evaluated in mice after 3–5 weekly subcutaneous injections, yeast lysates containing N-PbCS RNPs elicited strong anti-PbCS humoral responses, which were PbCS-dose dependent and reached a plateau by the pre-challenge time point. Protective efficacy of yeast lysates was dose-dependent, although anti-PbCS antibody titers were not predictive of protection. Multimerization of PbCS on RNPs was essential for providing benefit against infection, as immunization with monomeric PbCS delivered in yeast lysates was not protective. Three weekly injections with N-PbCS yeast lysates in combination with alum adjuvant produced sterile protection in two out of six mice, and significantly reduced parasitaemia in the other individuals from the same group. This parasitaemia decrease was of the same extent as in mice immunized with non-adjuvanted N-PbCS yeast lysates, providing evidence that the yeast lysate formulation did not require accessory adjuvants for eliciting efficient parasitaemia reduction.

Conclusions

This study demonstrates that yeast lysates are an attractive auto-adjuvant and efficient platform for delivering multimeric PbCS on measles N-based RNPs. By combining yeast lysates that carry RNPs with a large panel of Plasmodium antigens, this technology could be applied to developing a multivalent vaccine against malaria.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-1908-7) contains supplementary material, which is available to authorized users.

Detection of Emerging Vaccine-Related Polioviruses by Deep Sequencing

Oral poliovirus vaccine can mutate to regain neurovirulence. To date, evaluation of these mutations has been performed primarily on culture-enriched isolates by using conventional Sanger sequencing. We therefore developed a culture-independent, deep-sequencing method targeting the 5′ untranslated region (UTR) and P1 genomic region to characterize vaccine-related poliovirus variants. Error analysis of the deep-sequencing method demonstrated reliable detection of poliovirus mutations at levels of <1%, depending on read depth. Sequencing of viral nucleic acids from the stool of vaccinated, asymptomatic children and their close contacts collected during a prospective cohort study in Veracruz, Mexico, revealed no vaccine-derived polioviruses. This was expected given that the longest duration between sequenced sample collection and the end of the most recent national immunization week was 66 days. However, we identified many low-level variants (<5%) distributed across the 5′ UTR and P1 genomic region in all three Sabin serotypes, as well as vaccine-related viruses with multiple canonical mutations associated with phenotypic reversion present at high levels (>90%). These results suggest that monitoring emerging vaccine-related poliovirus variants by deep sequencing may aid in the poliovirus endgame and efforts to ensure global polio eradication.

Parental Approach to the Prevention and Management of Fever and Pain Following Childhood Immunizations: A Survey Study

Antipyretic analgesics are commonly used to prevent and treat adverse events following immunizations. Current practice discourages routine use due to possible blunting of vaccine immune responses. We surveyed 150 parents/caregivers of recently vaccinated 6- and 15-month-old children to determine the prevalence of and beliefs regarding antipyretic analgesics use around vaccinations. 11% used them prophylactically, before vaccination. Use in the first 48 hours after vaccination was 64%, primarily to prevent and/or treat fever and pain. Acetaminophen was administered 2.6 times more frequently than ibuprofen. Ibuprofen was used more in the 15-month compared with the 6-month-old children (28% vs 7.4%, respectively, P = .001). The majority of caregivers disagreed with their use for fever (53%) or pain (59%). Antipyretic analgesic use, including prophylaxis, around vaccinations was common in our study population. Effective interventions are needed to target parents/caregivers to eliminate unnecessary antipyretic analgesic use around vaccination time and foster nonmedication alternatives.

Update on Chlamydia trachomatis Vaccinology

Attempts to produce a vaccine to protect against Chlamydia trachomatis-induced trachoma were initiated more than 100 years ago and continued for several decades. Using whole organisms, protective responses were obtained. However, upon exposure to C. trachomatis, disease exacerbation developed in some immunized individuals, precluding the implementation of the vaccine. Evidence of the role of C. trachomatis as a sexually transmitted pathogen started to emerge in the 1960s, and it soon became evident that it can cause acute infections and long-term sequelae in women, men, and newborns. The main focus of this minireview is to summarize recent findings and discuss formulations, including antigens, adjuvants, routes, and delivery systems for immunization, primarily explored in the female mouse model, with the goal of implementing a vaccine against C. trachomatis genital infections.

The Social Value Of Vaccination Programs: Beyond Cost-Effectiveness

In the current global environment of increased strain on health care budgets, all medical interventions have to compete for funding. Cost-effectiveness analysis has become a standard method to use in estimating how much value an intervention offers relative to its costs, and it has become an influential element in decision making. However, the application of cost-effectiveness analysis to vaccination programs fails to capture the full contribution such a program offers to the community. Recent literature has highlighted how cost-effectiveness analysis can neglect the broader economic impact of vaccines. In this article we also argue that socioethical contributions such as effects on health equity, sustaining the public good of herd immunity, and social integration of minority groups are neglected in cost-effectiveness analysis. Evaluations of vaccination programs require broad and multidimensional perspectives that can account for their social, ethical, and economic impact as well as their cost-effectiveness.

Severe somatoform and dysautonomic syndromes after HPV vaccination: case series and review of literature

Human papilloma virus (HPV) is recognized as a major cause for cervical cancer among women worldwide. Two HPV vaccines are currently available: Gardasil® and Cervarix®. Both vaccines enclose viral antigenic proteins, but differ as to the biological systems of culture and the adjuvant components. Recently, a collection of symptoms, indicating nervous system dysfunction, has been described after HPV vaccination. We retrospectively described a case series including 18 girls (aged 12-24 years) referred to our "Second Opinion Medical Network" for the evaluation of "neuropathy with autonomic dysfunction" after HPV vaccination. All girls complained of long-lasting and invalidating somatoform symptoms (including asthenia, headache, cognitive dysfunctions, myalgia, sinus tachycardia and skin rashes) that have developed 1-5 days (n = 11), 5-15 days (n = 5) and 15-20 days (n = 2) after the vaccination. These cases can be included in the recently described immune dysfunction named autoimmune/inflammatory syndrome induced by adjuvants (ASIA). HPV vaccine, through its adjuvant component, is speculated to induce an abnormal activation of the immune system, involving glia cells in the nervous system too. Further researches should aim at defining the pathological and clinical aspects of these post-vaccination diseases and identifying a genetic background predisposing to these adverse reactions.

A Highly Efficacious Herpes Simplex Virus 1 Vaccine Blocks Viral Pathogenesis and Prevents Corneal Immunopathology via Humoral Immunity

Correlates of immunologic protection requisite for an efficacious herpes simplex virus 1 (HSV-1) vaccine remain unclear with respect to viral pathogenesis and clinical disease. In the present study, mice were vaccinated with a novel avirulent, live attenuated virus (0ΔNLS) or an adjuvanted glycoprotein D subunit (gD-2) similar to that used in several human clinical trials. Mice vaccinated with 0ΔNLS showed superior protection against early viral replication, neuroinvasion, latency, and mortality compared to that of gD-2-vaccinated or naive mice following ocular challenge with a neurovirulent clinical isolate of HSV-1. Moreover, 0ΔNLS-vaccinated mice exhibited protection against ocular immunopathology and maintained corneal mechanosensory function. Vaccinated mice also showed suppressed T cell activation in the draining lymph nodes following challenge. Vaccine efficacy correlated with serum neutralizing antibody titers. Humoral immunity was identified as the correlate of protection against corneal neovascularization, HSV-1 shedding, and latency through passive immunization. Overall, 0ΔNLS affords remarkable protection against HSV-1-associated ocular sequelae by impeding viral replication, dissemination, and establishment of latency.

IMPORTANCE

HSV-1 manifests in a variety of clinical presentations ranging from a rather benign "cold sore" to more severe forms of infection, including necrotizing stromal keratitis and herpes simplex encephalitis. The present study was undertaken to evaluate a novel vaccine to ocular HSV-1 infection not only for resistance to viral replication and spread but also for maintenance of the visual axis. The results underscore the necessity to reconsider strategies that utilize attenuated live virus as opposed to subunit vaccines against ocular HSV-1 infection.

Oral Modeling of an Adenovirus-Based Quadrivalent Influenza Vaccine in Ferrets and Mice

Introduction

Oral vaccines delivered as tablets offer a number of advantages over traditional parenteral-based vaccines including the ease of delivery, lack of needles, no need for trained medical personnel, and the ability to formulate into temperature-stable tablets. We have been evaluating an oral vaccine platform based on recombinant adenoviral vectors for the purpose of creating a prophylactic vaccine to prevent influenza, and have demonstrated vaccine efficacy in animal models and substantial immunogenicity in humans. These studies have evaluated monovalent vaccines to date. To protect against the major circulating A and B influenza strains, a multivalent influenza vaccine will be required.

Methods

In this study, the immunogenicity of orally delivered monovalent, bivalent, trivalent, and quadrivalent vaccines was tested in ferrets and mice. The various vaccine combinations were tested by blending monovalent recombinant adenovirus vaccines, each expressing hemagglutinin from a single strain. Human tablet delivery was modeled in animals by oral gavage in mice and by endoscopic delivery in ferrets.

Results

We demonstrated minimal interference between the various vaccine vectors when used in combination and that the oral quadrivalent vaccine compared favorably to an approved trivalent inactivated vaccine.

Conclusion

The quadrivalent vaccine presented here produced immune responses that we predict should be capable of providing protection against multiple influenza strains, and the platform should have applications to other multivalent vaccines.

Funding

Vaxart, Inc.

EV71 vaccine, a new tool to control outbreaks of hand, foot and mouth disease (HFMD)

On December 3rd 2015, the China Food and Drug Administration (CFDA) approved the first inactivated Enterovirus 71 (EV71) whole virus vaccine for preventing severe hand, foot and mouth disease (HFMD). As one of the few preventive vaccines for children's infectious diseases generated by the developing countries in recent years, EV71 vaccine is a blessing to children's health in China and worldwide. However, there are still a few challenges facing the worldwide use of EV71 vaccine, including the applicability against various EV71 pandemic strains in other countries, international requirements on vaccine production and quality control, standardization and harmonization on different pathogen monitoring and detecting methods, etc. In addition, the affordability of EV71 vaccine in other countries is a factor to be considered in HFMD prevention. Therefore, with EV71 vaccine commercially available, there is still a long way to go before reaching effective protection against severe HFMD after EV71 vaccines enter the market. In this paper, the bottlenecks and prospects for the wide use of EV71 vaccine after its approval are evaluated.

Correlates of Protection against Influenza in the Elderly: Results from an Influenza Vaccine Efficacy Trial

Although a number of studies have investigated and quantified immune correlates of protection against influenza in adults and children, data on immune protection in the elderly are sparse. A recent vaccine efficacy trial comparing standard-dose with high-dose inactivated influenza vaccine in persons 65 years of age and older provided the opportunity to examine the relationship between values of three immunologic assays and protection against community-acquired A/H3N2 influenza illness. The high-dose vaccine induced significantly higher antibody titers than the standard-dose vaccine for all assays. For the hemagglutination inhibition assay, a titer of 40 was found to correspond with 50% protection when the assay virus was antigenically well matched to the circulating virus—the same titer as is generally recognized for 50% protection in younger adults. A dramatically higher titer was required for 50% protection when the assay virus was a poor match to the circulating virus. With the well-matched virus, some protection was seen at the lowest titers; with the poorly matched virus, high levels of protection were not achieved even at the highest titers. Strong associations were also seen between virus neutralization test titers and protection, but reliable estimates for 50% protection were not obtained. An association was seen between titers of an enzyme-linked lectin assay for antineuraminidase N2 antibodies and protection; in particular, the proportion of treatment effect explained by assay titer in models that included both this assay and one of the other assays was consistently higher than in models that included either assay alone. (This study has been registered at ClinicalTrials.gov under registration no. NCT01427309.)

Polyionic vaccine adjuvants: another look at aluminum salts and polyelectrolytes

Adjuvants improve the adaptive immune response to a vaccine antigen by modulating innate immunity or facilitating transport and presentation. The selection of an appropriate adjuvant has become vital as new vaccines trend toward narrower composition, expanded application, and improved safety. Functionally, adjuvants act directly or indirectly on antigen presenting cells (APCs) including dendritic cells (DCs) and are perceived as having molecular patterns associated either with pathogen invasion or endogenous cell damage (known as pathogen associated molecular patterns [PAMPs] and damage associated molecular patterns [DAMPs]), thereby initiating sensing and response pathways. PAMP-type adjuvants are ligands for toll-like receptors (TLRs) and can directly affect DCs to alter the strength, potency, speed, duration, bias, breadth, and scope of adaptive immunity. DAMP-type adjuvants signal via proinflammatory pathways and promote immune cell infiltration, antigen presentation, and effector cell maturation. This class of adjuvants includes mineral salts, oil emulsions, nanoparticles, and polyelectrolytes and comprises colloids and molecular assemblies exhibiting complex, heterogeneous structures. Today innovation in adjuvant technology is driven by rapidly expanding knowledge in immunology, cross-fertilization from other areas including systems biology and materials sciences, and regulatory requirements for quality, safety, efficacy and understanding as part of the vaccine product. Standardizations will aid efforts to better define and compare the structure, function and safety of adjuvants. This article briefly surveys the genesis of adjuvant technology and then re-examines polyionic macromolecules and polyelectrolyte materials, adjuvants currently not known to employ TLR. Specific updates are provided for aluminum-based formulations and polyelectrolytes as examples of improvements to the oldest and emerging classes of vaccine adjuvants in use.

A sudden onset of a pseudo-neurological syndrome after HPV-16/18 AS04-adjuvated vaccine: might it be an autoimmune/inflammatory syndrome induced by adjuvants (ASIA) presenting as a somatoform disorder?

In last centuries, vaccines reduced the incidence of several infectious diseases. In last decades, some vaccines aimed at preventing also some cancers, where viruses play a causative role. However, several adverse events have been described after vaccines, but a causal relationship has been established only in a minority of cases. Here, we describe a pseudo-neurological syndrome occurred shortly after the administration of the bivalent HPV vaccine. Some autoimmune disorders, including neurological demyelinating diseases, have been reported after HPV vaccines, but the patient showed no organic lesions. The patient was diagnosed as having a functional somatoform syndrome, which was supposed to be autoimmune/inflammatory syndrome induced by adjuvants (ASIA), seen the temporal link with vaccination and the presence of anti-phospholipid autoantibodies. Immunological mechanisms of vaccines-and of adjuvants-have not been completely elucidated yet, and although there is no evidence of statistical association with many post-vaccination events, a causal link with vaccine cannot be excluded in some individuals.

History of vaccination

Vaccines have a history that started late in the 18th century. From the late 19th century, vaccines could be developed in the laboratory. However, in the 20th century, it became possible to develop vaccines based on immunologic markers. In the 21st century, molecular biology permits vaccine development that was not possible before.

Conserved immunogens in prime-boost strategies for the next-generation HIV-1 vaccines

INTRODUCTION

Effective vaccines are the best solution for stopping the spread of HIV/AIDS and other infectious diseases. Their development and in-depth understanding of pathogen-host interactions rely on technological advances.

AREAS COVERED

Rational vaccine development can be effectively approached by conceptual separation of, on one hand, design of immunogens from improving their presentation to the immune system and, on the other, induction of antibodies from induction of killer CD8(+) T cells. The biggest roadblock for many vaccines is the pathogens' variability. This is best tackled by focusing both antibodies and T cells on the functionally most conserved regions of proteins common to many variants, including escape mutants. For vectored vaccines, these 'universal' subunit immunogens are most efficiently delivered using heterologous prime-boost regimens, which can be further optimised by adjuvantation and route of delivery.

EXPERT OPINION

Development of vaccines against human diseases has many features in common. Acceleration of vaccine discovery depends on basic research and new technologies. Novel strategies should be safely, but rapidly tested in humans. While out-of-the-box thinking is important, vaccine success largely depends on incremental advances best achieved through small, systematic, iterative clinical studies. Failures are inevitable, but the end rewards are huge. The future will be exciting.

Aluminum hydroxide influences not only the extent but also the fine specificity and functional activity of antibody responses to tick-borne encephalitis virus in mice

Aluminum hydroxide is the most widely used adjuvant in human vaccines and serves as a potent enhancer of antibody production. Its stimulatory effect strongly depends on the adsorption of the antigen to the adjuvant, which may influence antigen presentation and, as a consequence, the fine specificity of antibody responses. Such variations can have functional consequences and can modulate the effectiveness of humoral immunity. Therefore, we investigated the influence of aluminum hydroxide on the fine specificity of antibody responses in a model study in mice using an inactivated purified virus particle, the flavivirus tick-borne encephalitis (TBE) virus, as an immunogen. To dissect and quantify the specificities of polyclonal antibodies in postimmunization sera, we established a platform of immunoassays using recombinant forms of the major target of neutralizing antibodies (protein E) as well as individual domains of E (DIII and the combination of DI and DII [DI+DII]). Our analyses revealed a higher proportion of neutralizing than virion binding (as detected by enzyme-linked immunosorbent assay) antibodies after immunization with aluminum hydroxide. Furthermore, the induction of antibodies to DIII, a known target of potently neutralizing antibodies, as well as their contributions to virus neutralization were significantly greater in mice immunized with adjuvant and correlated with a higher avidity of these antibodies. Thus, our data provide evidence that aluminum hydroxide can lead to functionally relevant modulations of antibody fine specificities in addition to its known overall immune enhancement effect.

Biodegradable particles as vaccine antigen delivery systems for stimulating cellular immune responses

There is a need for both new and improved vaccination formulations for a range of diseases for which current vaccines are either inadequate or non-existent. Biodegradable polymer-based vaccines fulfill many of the desired properties in achieving effective long-term protection in a manner that is safe, economical, and potentially more practicable on a global scale. Here we discuss some of the work performed with micro/nanoparticles made from either synthetic (poly[lactic-co-glycolic acid] [PLGA] and polyanhydrides) or natural (chitosan) biodegradable polymers. Our attention is focused on, but not limited to, the generation of antitumor immunity where we stress the importance of particle size and co-delivery of antigen and adjuvant.

Development of a new hydrogen peroxide–based vaccine platform

Safe and effective vaccines are crucial for maintaining public health and reducing the global burden of infectious disease. Here we introduce a new vaccine platform that uses hydrogen peroxide (H(2)O(2)) to inactivate viruses for vaccine production. H(2)O(2) rapidly inactivates both RNA and DNA viruses with minimal damage to antigenic structure or immunogenicity and is a highly effective method when compared with conventional vaccine inactivation approaches such as formaldehyde or β-propiolactone. Mice immunized with H(2)O(2)-inactivated lymphocytic choriomeningitis virus (LCMV) generated cytolytic, multifunctional virus-specific CD8(+) T cells that conferred protection against chronic LCMV infection. Likewise, mice vaccinated with H(2)O(2)-inactivated vaccinia virus or H(2)O(2)-inactivated West Nile virus showed high virus-specific neutralizing antibody titers and were fully protected against lethal challenge. Together, these studies demonstrate that H(2)O(2)-based vaccines are highly immunogenic, provide protection against a range of viral pathogens in mice and represent a promising new approach to future vaccine development.

Improving pediatric practice immunization rates through distance-based quality improvement: a feasibility trial from PROS

The feasibility and effectiveness of a distance-based quality improvement model were examined in a cohort of Pediatric Research in Office Settings (PROS) practices, with the goal of improving immunization rates and practitioner behaviors and attitudes. Of an initially assessed 82 practices, 29 with baseline rates of < or =88% for children 8 to 15 months of age were randomized into year-long paper-based education or distance-based quality improvement intervention groups. Outcomes were utility/helpfulness of quality improvement modalities, immunization rate change, and behavior/attitude change. Quality improvement participants attended approximately 75% of monthly conference calls but used the quality improvement Listserv and Web site infrequently (mean 1.09 and 0.92 uses, respectively). Helpfulness ratings of quality improvement modalities mirrored usage. Analyses revealed a 4.9% increase in quality improvement group immunization rates (P = .061), a 0.8% education group increase (P = .752), and a 4.1% difference between groups (P = .261). More quality improvement practices adopted systems identifying children behind in immunizations. A distance-based quality improvement model is feasible and may improve immunization rates.

Statewide quality improvement outreach improves preventive services for young children

OBJECTIVE

Although clinical trials demonstrate the efficacy of quality improvement outreach in improving service delivery, evidence for broad community effectiveness has been lacking. The objective of this study was to test the effectiveness of a statewide pediatric quality improvement outreach program in improving preventive services for children who are younger than 5 years.

METHODS

All pediatric practices in Vermont (n = 35) were invited to participate in a preventive services quality improvement initiative. Ninety-one percent agreed. Participating practices serve >80% of all Vermont children who are younger than 5 years. The main outcome measured was change in 9 preventive services areas: (1) immunizations up to date; (2) anemia screening; (3) tuberculosis risk assessment and indicated screening; (4) lead screening; (5) infant sleep position counseling; (6) environmental tobacco smoke-exposure risk assessment; (7) blood pressure screening; (8) vision screening; and (9) dental risk assessment.

RESULTS

All practices demonstrated improvement in 1 or more preventive services areas. The mean number of areas chosen was 5 (range: 1-9). Practices that selected a specific preventive service area as a quality improvement goal were more likely to demonstrate improvement in that area than practices that did not choose to focus on that preventive services area.

CONCLUSIONS

The work in this project has provided the evidence for an effective statewide pediatric quality improvement outreach program to improve preventive services for children who are younger than 5 years. Practices' decision to focus on a specific preventive service area as a quality improvement goal seems necessary for improvement in that area. This approach may be effective in other states or regions.

The business of science and the science of business in the quest for an AIDS vaccine

This paper simplifies and encapsulates the past, present and future for developing vaccines, especially against AIDS. Needed technical information and how it can best be obtained are delineated. The views are my own and may not be shared by others. The science enterprise, including that for vaccines, is enmeshed in the major evolution and restructuring of many of the world's institutions. Changes brought by the knowledge revolution impinge on scientific information, technology, public policy, societal demands, private and public funding, academic and industrial organization and economic opportunity. Public-supported research is not an entitlement. It is in the scientific establishment's best interest to organize for greatest efficiency and effectiveness to bring paybacks commensurate with public investment.