Expert Review of Vaccines

BACKGROUND: The question of whether influenza vaccine effectiveness (VE) wanes over the winter season is still open and some contradictory findings have been reported. This study investigated the possible decline in protection provided by the available influenza vaccines. RESEARCH DESIGN AND METHODS: An individual-level pooled analysis of six test-negative case-control studies conducted in Italy between the 2018/2019 and 2022/2023 seasons was performed. Multivariable logistic regression analyses were performed to estimate weekly change in the odds of testing positive for influenza 14 days after vaccination...

BACKGROUND: Cell-based quadrivalent inactivated influenza vaccines (IIV4c) avoid egg-adaptive mutations found in egg-based production, improving vaccine effectiveness (VE). Studies demonstrate improved VE for IIV4c relative to egg-based quadrivalent inactivated influenza vaccines (IIV4). RESEARCH DESIGN AND METHODS: We built on a static compartmental model developed by the CDC to estimate the influenza burden in persons 0-64 years that would be additionally averted by vaccination with IIV4c vs...

BACKGROUND: Respiratory syncytial virus (RSV), a common respiratory pathogen, can lead to severe symptoms, especially in older adults (OA). A recently developed RSV prefusion F protein (RSVPreF3 OA) vaccine confers high protection against RSV lower respiratory tract disease (LRTD) over two full RSV seasons. The aim of this study was to assess the potential public health impact of RSVPreF3 OA vaccination in the Japanese OA population. RESEARCH DESIGN AND METHODS: A static Markov model was used to estimate the number of symptomatic RSV cases, hospitalizations and deaths in the Japanese population aged ≥ 60 years over a 3-year time horizon...

BACKGROUND: The breadth of protection of National Immunisation Programmes (NIPs) across Europe varies, however, this has not been assessed within published literature. Therefore, a framework was developed to assess the comprehensiveness of pediatric NIPs in Europe. This study aimed to validate and further develop criteria used to cluster countries into three tiers. RESEARCH DESIGN AND METHODS: Independent Europe-based experts ( n  = 23) in the field of pediatric vaccination were invited to participate in a double-blinded modified Delphi panel, with two online survey rounds and a virtual consensus meeting...

INTRODUCTION: The escalating prevalence of infectious diseases is an important cause of concern in society. Particularly in several developing countries, infectious diarrhea poses a major problem, with a high fatality rate, especially among young children. The condition is divided into four classes, namely, acute diarrhea, invasive diarrhea, acute bloody diarrhea, and chronic diarrhea. Various pathogenic agents, such as bacteria, viruses, protozoans, and helminths, contribute to the onset of this condition...

BACKGROUND: Pneumococcal vaccines are effective in preventing pneumococcal diseases in adults. The evaluation of the antibodies persistence to the 23-valent pneumococcal polysaccharide vaccine (PPV23) could provide evidence on PPV23 revaccination. RESEARCH DESIGN AND METHODS: Adults aged ≥ 60 years were selected and vaccinated with PPV23 in Shanghai, and followed up for 5 years with blood samples collection of a 1-year interval...

INTRODUCTION: Pseudoviruses are recombinant, replication-incompetent, viral particles designed to mimic the surface characteristics of native enveloped viruses. They are a safer, and cost-effective research alternative to live viruses. With the potential emergence of the next major infectious disease, more vaccine scientists must become familiar with the pseudovirus platform as a vaccine development tool to mitigate future outbreaks. AREAS COVERED: This review aims at vaccine developers to provide a basic understanding of pseudoviruses, list their production methods, and discuss their utility to assess vaccine efficacy against enveloped viral pathogens...

No abstract text is available yet for this article.

BACKGROUND: Cell-based quadrivalent influenza vaccines (QIVc) can increase effectiveness against seasonal influenza by avoiding mismatch from egg adaption of vaccine viruses. This study evaluates the population-level cost-effectiveness and impacts on health outcomes of QIVc versus an egg-based vaccine (QIVe) in children aged 6 months to 17 years in the US. RESEARCH DESIGN AND METHODS: A dynamic age-structured susceptible-exposed-infected-recovered model was used to simulate influenza transmission in low and high incidence seasons for two scenarios: 1...

INTRODUCTION: Influenza causes significant morbidity and mortality, but influenza vaccine uptake remains below most countries' targets. Vaccine policy recommendations vary, as do procedures for reviewing and appraising the evidence. AREAS COVERED: During a series of roundtable discussions, we reviewed procedures and methodologies used by health ministries in four European countries to inform vaccine recommendations. We review the type of evidence currently recommended by each health ministry and the range of approaches toward considering randomized controlled trials (RCTs) and real-world evidence (RWE) studies when setting influenza vaccine recommendations...

BACKGROUND: Delays in influenza vaccine delivery and administration can hinder vaccine coverage and protection. This study examines the differentials in distributing and administering adjuvanted trivalent (aTIV) and quadrivalent influenza vaccines (aQIV) to older adults in Italy's primary care setting and its potential impact on hospitalization risk over 5 epidemic seasons. METHODS: Using a primary care database, individuals aged ≥ 65 years were selected...

No abstract text is available yet for this article.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing COVID-19 has been a dynamically changing virus, requiring the development of adapted vaccines. This study estimated the potential public health impact alternative vaccination strategies for COVID-19 in Singapore. RESEARCH DESIGN AND METHODS: The outcomes of alternative vaccination strategies with a future adapted vaccine were estimated using a combined Markov decision tree model. The population was stratified by high- and standard-risk...

BACKGROUND: This review aimed to systematically evaluate the immunogenicity and safety of the candidate ebolavirus vaccine (EVV). METHODS: We searched five databases for randomized controlled trials (RCTs) evaluating the effects of EVV on healthy adults. The primary outcomes were relative risk (RR) of sero-conversion or sero-response of EVV in healthy adults between the groups that received EVV and the controls. RESULTS: Twenty-nine RCTs ( n  = 23573) were included...

INTRODUCTION: Streptococcus pneumoniae is a causative agent of pneumonia and acute otitis media (AOM), as well as invasive diseases such as meningitis and bacteremia. PCV15 (V114) is a new 15-valent pneumococcal conjugate vaccine (PCV) approved for use in individuals ≥6 weeks of age for the prevention of pneumonia, AOM, and invasive pneumococcal disease. AREAS COVERED: This review summarizes the V114 Phase 3 development program leading to approval in infants and children, including pivotal studies, interchangeability and catch-up vaccination studies, and studies in at-risk populations...

INTRODUCTION: Malaria represents a tremendous public health challenge in tropical and sub-tropical regions, and currently deployed control strategies are likely insufficient to drive elimination of malaria. Development and improvement of malaria vaccines might be key to reduce disease burden. Vaccines targeting asexual blood stages of the parasite have shown limited efficacy when studied in human trials conducted over the past decades. AREAS COVERED: Vaccine candidates based on the merozoite surface protein 1 (MSP1) were initially envisioned as one of the most promising approaches to provide immune protection against asexual blood-stage malaria...

INTRODUCTION: This paper summarizes the safety and immunogenicity data of Influvac Tetra across all age groups starting from 6 months of age, obtained during its clinical development program. AREAS COVERED: The article covers the clinical development program of Influvac Tetra based on five registration studies that included different age groups, different comparators, and participants from Europe and Asia. Safety and immunogenicity were assessed in all studies and in one study, the efficacy of Influvac Tetra was assessed...

BACKGROUND: Clinical evidence supports use of enhanced influenza vaccines in older adults. Few economic outcome studies have compared adjuvanted trivalent inactivated (aIIV3) and standard egg-derived quadrivalent inactivated influenza vaccines (IIV4e). RESEARCH DESIGN AND METHODS: A retrospective cohort study was conducted leveraging deidentified US hospital data linked to claims data during the 2018-19 and 2019-20 influenza seasons. Relative vaccine effectiveness (rVE) was compared in adults aged ≥65 years receiving aIIV3 or IIV4e using inverse probability of treatment weighting (IPTW) and Poisson regression...

BACKGROUND: Next-generation, higher-valency pneumococcal conjugate vaccines (PCVs), 15-valent PCV V114 and 20-valent PCV (PCV20), have been assessed by comparing their immune responses across serotypes shared with the 13-valent PCV (PCV13). Without efficacy or real-world vaccine effectiveness (VE) it becomes important to relate IgG titers to VE to aid in the interpretation of the immune response elicited by V114 and PCV20. METHODS: We estimated the protective antibody concentrations for each serotype in 7-valent PCV (PCV7) and PCV13 which were then used to predict the serotype-specific VE for each PCV7 and PCV13-non PCV7 serotype present in V114 and PCV20...

INTRODUCTION: : The rapid development of COVID-19 vaccines has provided crucial tools for pandemic control, but the occurrence of vaccine-related adverse events (AEs) underscores the need for comprehensive monitoring. METHODS: : This study analyzed the Vaccine Adverse Event Reporting System (VAERS) data from 2020-2022 using statistical methods such as zero-truncated Poisson regression and logistic regression to assess associations with age, gender groups, and vaccine manufacturers...