Expert Review of Vaccines最新文献

Background: The ongoing emergence of SARS-CoV-2 variants has raised concerns about the breadth of the immune response provided by existing vaccines.

Research design and methods: In this study, participants aged 18-75 years with no prior COVID-19 infection or vaccination history were enrolled to receive the CoronaVac vaccine. The interval between the first and second vaccine doses was 28 days, while the third dose was given 6 months after the second.

Results: Between February 1 to 15 February 2022, we recruited 40 eligible participants who had not received any COVID-19 vaccination and had no prior COVID-19 infection. After the third dose, neutralizing antibody levels significantly increased against the ancestral strain and certain Omicron variants (BA.1, BA.4/5, BF.7). Compared to levels observed 28 days post-second dose, neutralizing antibody levels rose further 28 days after the third dose, with the GMFI against the ancestral strain at 1.69 (95% CI: 1.27, 2.20). Among other variants, the GMFI against Omicron variants (BA.1, BA.4/5, BF.7) exceeded that for Beta and Delta, with the highest GMFI recorded for the BA.4/5 variant at 4.97 (95% CI: 3.08, 8.05).

Conclusions: The necessity of the third booster dose lies in its ability to enhance the breadth of the immune response.

Introduction: Comparative effectiveness data of COVID-19 vaccines remain limited. We conducted a systematic review and network meta-analysis (NMA) feasibility assessment of effectiveness studies of Omicron-adapted COVID-19 vaccines.

Research design and methods: Searches in MEDLINE and Embase up to February 2025 identified studies comparing the effectiveness of Omicron-adapted COVID-19 vaccines, either directly or against no recent vaccine. Two investigators independently selected articles reporting adjusted vaccine effectiveness (VE). A feasibility assessment determined the appropriateness of a common comparator and evaluated effect modifiers (EMs). Data extraction and risk-of-bias assessment were performed by one investigator and validated by a second investigator. Bayesian NMAs using random-effects models were performed for base-case analyses, data permitting.

Results: The review identified 25 studies for Omicron-adapted COVID-19 vaccines: 16 for XBB formulations, eight of which were included in NMAs, all for mRNA formulations, representing 29.9 million participants. BNT162b2 had the largest evidence base. Comparisons between XBB.1.5-adapted BNT162b2 (Comirnaty) and mRNA-1273 (Spikevax) found that both vaccines are effective and comparable against XBB-related hospitalizations, infections, and medically attended visits in adults Among elderly, the estimated effectiveness against XBB-related hospitalizations favored BNT162b2.

Conclusions: Findings of this NMA of observational studies support the effectiveness of XBB.1.5-adapted mRNA vaccines. Limitations included assumptions on EMs and sparse evidence networks.

Introduction: Immunization Information Systems (IISs) are essential public health tools, supporting the management and analysis of vaccination data to aid clinical and strategic decision-making.

Methods: Following PRISMA guidelines, this systematic review investigated global state and operational characteristics of IISs. A comprehensive search across multiple databases up to 6^th of June 2023, identified 2,612 articles, with 238 included.

Results: A significant increase in IIS research was observed in recent years, with a strong preference (84.5%) for electronic immunization registers (EIRs). Notably, 36% of IISs operate at the national level, and 47.7% meet the U.S. CDC definition, 17.0% are interoperable with personal health records, and 11.7% provide direct access to vaccination data for vaccinees or their guardians. Other key features include automated reminder systems for recipients and providers (12.1%), near real-time or real-time data entry (11.0%), the inclusion of demographic and socioeconomic data (16.7%), and the capacity to document vaccine refusal or hesitancy (10.2%).

Conclusions: IISs contribute to improving population-level surveillance of vaccine-preventable diseases. Persistent limitations related to data standardization, interoperability, and cost-effectiveness evaluation must be addressed. Strengthening these aspects is crucial to fully harness the potential of IISs in various healthcare settings, where enhanced vaccination tracking and targeting are most urgently needed.

Background: Evidence regarding the comparative safety of different COVID-19 vaccines remains limited. This study aims to characterize and compare the safety profiles of five COVID-19 vaccines in terms of adverse reactions after immunization.

Research design and methods: We conducted a retrospective analysis of adverse reactions reported among adults aged 18-59 years from nine clinical trials. The analyzed vaccines included inactivated, recombinant protein, intranasal influenza-vectored, aerosolized and intramuscular Ad5 vectored COVID-19 vaccines. Factor analysis and association rule analysis were used to characterize adverse reaction patterns, while multivariate logistic regression was employed to assess the influence of vaccine type and demographic factors.

Results: Inactivated, recombinant, and intramuscular Ad5 vectored vaccines commonly caused injection site pain, fatigue, headache, and pyrexia from the SOC of 'General disorders and administration site conditions.' Intranasal influenza-vectored vaccines mainly cause respiratory symptoms such as rhinorrhea and nasal congestion, while dry mouth and oropharyngeal pain from 'Gastrointestinal disorders' were primarily observed in aerosolized Ad5 vectored vaccines. Younger age (p < 0.001), female sex (p = 0.001), comorbidities (p < 0.001), and intramuscular Ad5 vectored vaccines (p < 0.001) were significantly associated with higher adverse reaction risks.

Conclusions: COVID-19 vaccines developed through different technological approaches have distinct adverse reaction profiles.

Background: Adolescents and adults who contract chickenpox are at a higher risk of severe complications. Vaccination with the varicella vaccine (VarV) effectively prevents chickenpox.

Research design and methods: In this phase III, single-center, randomized, double-blind, active-controlled trial, 1,200 healthy participants were randomly assigned in a 1:1 ratio to receive two doses of either the test vaccine or the active control vaccine. Varicella-zoster virus (VZV) antibody was detected before vaccination and 42 days after the two doses of vaccination.

Results: The lower limits of the 95% CI for the differences in seroconversion rates and geometric mean titer (GMT) ratios between the two groups were greater than their respective pre-set non-inferiority margins. The overall incidence of Adverse events (AEs) and adverse reactions (ARs) in the test group was significantly lower than those in the control group. Additionally, the incidence rates of swelling and fatigue were lower in the test group compared to the control group after vaccination.

Conclusions: The test freeze-dried live attenuated VarV demonstrated good immunogenicity and higher safety compared to the active control vaccine in healthy participants aged 13-55 years.

Clinical trials registration: www.clinicaltrials.gov identifier: NCT06592456.

Background: Respiratory infections like pneumococcal disease (PD), respiratory syncytial virus (RSV), influenza (Flu), and COVID-19 significantly impact Japan's aging population, imposing substantial health and economic burdens. Effective vaccines exist, yet uptake remains limited due to funding constraints and vaccine hesitancy. This study assessed the societal return on investment in adult respiratory vaccination programs to support informed policy decisions.

Research design & methods: We conducted a benefit-cost analysis using static cohort models and life tables to estimate benefit-cost ratios (BCRs) and societal net benefits (NBs), monetizing health impacts through the value of statistical life and cost-of-illness methods. Costs comprised vaccination program expenses. Scenario and sensitivity analyses explore coverage scenarios and parameter assumptions.

Results: Adult vaccination programs generated BCRs around 18:1 within 5 years and 20:1 over a lifetime. Lifetime NBs exceeded ¥113 trillion, preventing nearly three million hospitalizations and freeing millions of hospital bed-days, alongside avoiding over ¥100 billion in productivity losses. Expanding vaccine coverage significantly increased the NBs by > 30%, whereas reduced COVID-19 vaccine uptake notably diminished returns.

Conclusion: Japan's adult respiratory vaccination programs generate substantial socioeconomic returns, strengthening public health, healthcare resilience, and workforce productivity. Increasing uptake across the population can generate significantly higher NBs. Realizing these benefits requires addressing vaccine uptake barriers and enhancing public investment.

Background: CoronaVac (Sinovac) was initially effective against symptomatic COVID-19 and severe outcomes, but its performance against the immune-evasive Omicron variant remains uncertain. This study evaluated the effectiveness of CoronaVac against hospitalized COVID-19 among Filipino adults during the Omicron-dominant wave.

Research design and methods: We conducted a test-negative case-control study from November 2022 to November 2023 in three tertiary government hospitals in the Philippines. Adults hospitalized with acute respiratory illness (ARI) were enrolled. Cases tested positive for SARS-CoV-2 by RT-PCR; controls tested negative. Vaccination status was confirmed via vaccination cards or the national registry. Conditional logistic regression estimated vaccine effectiveness (VE). Genomic sequencing identified circulating variants.

Results: Among 2,365 participants, 165 (7.0%) were COVID-19 positive. In an age-matched analysis (104 cases, 408 controls), two CoronaVac doses provided 61.3% protection (95% CI: 5.3-84.2%) against critical illness. A heterologous booster conferred 65.9% protection against severe disease, 90.1% against critical illness, and 60.5% against death. Sequencing of 23/46 samples confirmed Omicron XBB-like variants.

Conclusion: Two doses of CoronaVac offered moderate protection against severe COVID-19. Heterologous boosters significantly improved protection, especially against critical illness and death, supporting ongoing booster campaigns after inactivated vaccine priming.

Background: Rotavirus vaccination plays a key role in reducing rotavirus gastroenteritis (RVGE) related deaths. This analysis estimated the number of children under 5 years of age fully vaccinated with GSK rotavirus vaccine (RV1) since launch (2004) and its impact on RVGE-related deaths worldwide.

Research design and methods: To estimate the number of children under 5 years fully vaccinated with RV1 since launch, we used unpublished RV1 market supply data from GSK. The data were extrapolated until the time point when 1 billion doses will have been supplied. The number of RVGE-related deaths avoided was calculated using previously published data on the number of children needed to be fully vaccinated to avoid one fatal RVGE.

Results: Approximately 431 million children under 5 years received a complete RV1 course from 2004 to 2023, avoiding over 220,000 RVGE-related deaths globally. The forecasted analysis estimated that by January 2025, 1 billion RV1 doses will have been supplied worldwide, representing 239,000 RVGE-related deaths avoided. By December 2025, 0.5 billion babies will be protected with RV1, resulting in 259,000 RVGE-related deaths avoided since 2004.

Conclusion: RV1 has contributed to reducing the number of RVGE cases and related deaths and is anticipated to continue reducing this disease burden.

Background: Pharmacies can increase access to vaccines. This study aimed to describe trends in the proportion of adolescent and adult vaccinations administered in pharmacies in the United States from 2018 to 2024.

Research design and methods: This was a retrospective cross-sectional analysis of medical and pharmacy claims from commercial health insurance enrollees. We recorded vaccinations received by enrollees ≥9 years of age from 2018 to 2023 (routine vaccines) or 2024 (seasonal vaccines). We calculated the annual proportion of vaccinations occurring in pharmacies and the accumulated percent change in vaccination rate during each year from 2020 onward compared to 2018-2019.

Results: The proportion of routine vaccinations occurring in pharmacies was higher among adults than among adolescents. For most routine vaccines, this proportion increased during the study period. The lowest proportion was observed for adolescent human papillomavirus vaccination in 2018 (0.2%), and the highest for herpes zoster vaccination among adults ≥65 years of age in 2023 (88.6%). For all age groups, pharmacy-based vaccination was more common for seasonal influenza and SARS-CoV-2 vaccines than for all routine vaccines except herpes zoster.

Conclusions: Pharmacy-based vaccination is increasingly common in the United States, particularly among adults and for seasonal vaccines, and can help increase the overall level of vaccine uptake.