Expert Review of Vaccines最新文献

Objective: The aim of the present study was to evaluate the cost-effectiveness of 20-valent pneumococcal conjugate vaccine (PCV20) compared to 13-valent pneumococcal conjugate vaccine (PCV13) and 15-valent pneumococcal conjugate vaccine (PCV15) for prevention of pneumococcal disease in the pediatric population in Greece.

Methods: A published decision-analytic Markov model was adapted from payer perspective, to compare PCV20 (under a 3 + 1 dosing schedule per EMA approval) with PCV13 and PCV15 (both under a 2 + 1 dosing schedule) over a 10-year time horizon. Inputs for epidemiology, serotype coverage, vaccine effectiveness, utilities, and direct medical costs (€2024) were sourced from published literature and official data. Model outcomes included number of invasive pneumococcal disease (IPD), noninvasive hospitalized pneumonia, non-hospitalized pneumonia and otitis media (OM) cases, attributable deaths, costs, quality-adjusted life-years (QALYs) for each vaccination strategy and the incremental cost-effectiveness ratios for each comparison. Scenario analyses assessed PCV20 in a 2 + 1 schedule per recent national recommendations.

Results: The analysis indicated that, vaccination with PCV20 compared to PCV13 and PCV15 prevents an additional 1,953 and 1,514 cases of IPD 54,956 and 42,069 noninvasive hospitalized and non-hospitalized pneumonia cases, 343,353 and 271,864 OM cases and 1,377 and 987 deaths respectively, resulting in incremental gain of 23,065 (vs PCV13) and 17,118 (vs PCV15) QALYs respectively. The lower number of pneumococcal disease cases with PCV20 compared to PCV13 and PCV15, translated to a reduction in total medical care cost of €249 M vs PCV13 and €192 M vs PCV15 over the modeled time horizon. Scenario analyses showed that PCV20 remained dominant under a 2 + 1 dosing schedule.

Conclusion: Vaccination with PCV20, whether in a 2 + 1 or a 3 + 1 schedule, was estimated to be a dominant vaccination strategy over PCV15 or PCV13 for the prevention of pneumococcal disease in Greek infants, as expansion of serotype coverage prevents additional morbidity and costs.

Background: We estimated vaccine effectiveness (VE) of the COVID-19 monovalent XBB.1.5 vaccine recommended in Spain in October 2023 for ≥60-year-olds against medically attended COVID-19 and COVID-19 hospitalization, during winter and summer epidemic waves.

Research design and methods: Patients ≥60-year-olds consulting in primary-care or requiring hospitalization due to respiratory infection were systematically RT-PCR tested for SARS-CoV-2 and classified as cases if PCR-positive or controls if PCR-negative. Logistic regression compared autumnal vaccination ≥14 days before onset in cases and controls adjusting for sex, age group, comorbidities, region in Spain and week; VE=(1-Odds Ratio)x100.

Results: We included 1,141/3,286 and 1,386/5,260 cases/controls from primary-care and hospitals. During the winter wave, VE (95% Confidence Interval) was 28% (5;47%) against medically attended COVID-19 [45% (-31;80%) during XBB.1.5 dominance; 26% (-2;46%) during BA.2.86] and 39% (24;51%) against hospitalization [73% (41;89%) during XBB.1.5; 37% (17;48%) during BA.2.86]. During the summer wave, VE decreased; -6% (-33;15%) against infection [21% (-11;44%) during BA.2.86; -39% (-91;-1%) during KP.3] and 6% (-14;22%) against hospitalization [8% (-20;30%) during BA.2.86; 5% (-35;21%) during KP.3].

Conclusions: COVID-19 VE was moderate during the 2023/24 winter wave, higher during XBB.1.5 dominance and against hospitalization. Effectiveness was null during the summer wave, likely reflecting waning immunity and SARS-CoV-2 variant substitution.

Background: This study investigates the impact of birth order on influenza vaccination behaviors and intentions among parents of children under 6 years of age, and identifies factors contributing to vaccination disparities to inform targeted strategies for reducing health inequities.

Research design and methods: A national cross-sectional survey was conducted in China (July - August 2024) using stratified sampling, with 3,569 parents of children aged 0-6 completing a questionnaire based on the Determinants of Vaccine Hesitancy Matrix developed by the World Health Organization (WHO-DVH Matrix). Logarithmic regression examined the relationship between age and vaccine hesitancy/vaccination rates. Random forest analysis identified key predictors, while one-way ANOVA examined influencing factors.

Results: Among respondents, 66.9% were first-time parents and 33.1% second-time parents. Vaccination rates for first-born children were lower than those for second-born children before 40 months (64.9% vs. 71.7%, p = 0.022), while vaccine hesitancy was higher among first-time parents before 49 months (58.6% vs. 49.9%, p < 0.001). These differences diminished after age three. Key predictors of vaccination intention included 'Immunization as a social norm' and the 'Reliability of vaccine supply.'

Conclusions: First-time parents demonstrate lower vaccination rates and higher hesitancy to children, particularly before age three, influenced by social norms and vaccine confidence. These findings provide empirical evidence for birth order-based strategies to improve vaccine equity.

Background: The role COVID-19 vaccination on healthcare resource utilization (HCRU) and cost remains unclear, especially during Omicron predominance and among high risk UK populations.

Research design and methods: A retrospective cohort study using UK The Health Improvement Network (THIN) primary care data included adults (≥18 years) with confirmed or suspected COVID-19 between September 2022 and May 2023. Three cohorts were defined: Highest risk (eligible for two seasonal doses), High Risk (eligible for one dose), and All COVID-19 patients. Long COVID was identified as ≥1 symptom or diagnostic/referral code, ≥4 weeks post COVID-19 diagnosis. Inverse probability of treatment weighting assessed associations between vaccination status (yes/no and time since vaccination) and long COVID, HCRU, and costs.

Results: In both Risk Cohorts, COVID-19 vaccination was not associated with long COVID incidence. However, in the High Risk (n = 1,889) and All Patients cohorts (n = 8,507) outpatient specialist referrals were significantly lower in the 3-6-month post-vaccination group versus > 6 months (rate ratio: 0.28; 95% CI: 0.10-0.79, p < 0.05 and 0.46; 95% CI: 0.27-0.79; p ≤ 0.01, respectively).

Conclusions: COVID-19 vaccination was not consistently associated with incidence of long COVID or all-cause HCRU. Findings suggest potential subgroup-specific benefits, highlighting the importance of annual vaccination. Further research with larger sample size and longer-term follow-up is warranted.

Introduction: One of the biggest challenges in the mRNA-LNP vaccine field is product stabilization to overcome the logistical hurdles linked to the ultra-cold distribution chain associated with first-generation mRNA SARS-CoV-2 vaccines. Despite recent progress in the field, many R&D efforts remain focused on the development of mRNA-LNP vaccines that would be as stable as liquid formulations for storage at refrigerated or room temperatures.

Areas covered: After an overview of the underlying mechanisms of mRNA-LNP instability, this review provides an update on the different approaches that are currently explored to improve mRNA-LNP thermostability, encompassing mRNA sequence optimization, nucleotide modification and mRNA-LNP design strategies as well as formulation process optimization. Alternative approaches for mRNA-LNP stabilization such as lyophilization, dual-vial formulations and the replacement of water with deep eutectic solvents in the mRNA-LNP process and products are also discussed.

Expert opinion: Achieving robust thermostability of mRNA vaccines will require a multifactorial optimization strategy, integrating advances in sequence engineering, novel formulation designs, buffer composition, excipient selection and manufacturing processes.

Introduction: Vaccination rates in Italian children must be substantially increased to control the transmission of seasonal influenza and mitigate the associated socio-economic burden. This work aimed to describe strategies to improve the effectiveness and reach of pediatric influenza vaccination campaigns in Italy.

Areas covered: Based on a literature review, influencing factors and potential strategies to enhance vaccination coverage were explored, focusing on settings, logistics, and communication aspects.

Expert opinion: School-based interventions should be deeply implemented in Italy by offering a cost-effective and safe approach to vaccination and successfully overcoming socio-economic and cultural challenges. Scheduled educational programs and institution-supported childhood influenza vaccination awareness campaigns that thoroughly inform about the risk of influenza and its socio-economic consequences, counter vaccine hesitancy, and discuss the benefits of vaccination are desirable, thus concretely prompting all children, families, and healthcare professionals to get vaccinated. Digitalizing procedures could lead to improved adherence by healthcare professionals to immunization programs. Nationwide implementation of these strategies would establish a robust, sustainable system for pediatric influenza vaccination. This would significantly increase childhood vaccination rates, leading to improved disease control and substantially reducing the overall national burden of influenza.

Background: This study evaluated the impact of vaccination strategies using an adapted COVID-19 vaccine in Mexico.

Research design and methods: This study used a previously published combined Markov-decision tree model adapted for the Mexican context. The base case examined the population aged ≥ 65 years and the high-risk population (defined as those with one or more comorbidities associated with high risk of severe disease) aged 12-64 years. Scenario analyses examined lower age cutoffs for eligibility in the standard risk population (≥50 years, ≥18 years, and ≥12 years). Sensitivity analyses varying the parameters by ± 20% was conducted to assess uncertainty.

Results: Compared to no vaccination, the base case was estimated to prevent 1,509,194 cases, 132,166 hospitalizations 24,575 deaths, and 276,223 lost quality-adjusted life-years (QALYs), increasing direct costs by $602,446,820 and decreasing societal cost by $2,264,266,271. The ICER was dominant from the societal perspective and $2,181 from the payer perspective, which was cost-effective at a willingness-to-pay threshold of 1× GDP per capita ($11,812). The benefits were further increased in scenarios expanding vaccination to additional age groups.

Conclusions: Vaccination strategies targeting a broader age range with an adapted vaccine would result in considerable health and economic benefits and be cost-effective in Mexico.

Introduction: Pertussis poses a significant threat to infants under six months due to their immature immune systems, limited maternal antibody protection, and constraints in the vaccination schedule. Despite vaccination efforts, this group remains highly susceptible to severe complications. Addressing these challenges is crucial for improving the health outcomes of infants in China.

Areas covered: This review examines the primary challenges in preventing pertussis infections among infants under six months in China, focusing on factors such as underdeveloped immune system and inadequate maternal antibody protection. It analyzes limitations in current vaccination strategies and the impact of socio-cultural factors, healthcare resource distribution, and surveillance inadequacies. A comprehensive literature search was conducted to identify potential solutions, including enhancing maternal immunization, adjusting early vaccination strategies, increasing vaccine coverage, and developing new vaccines. The review synthesizes current research findings and data to provide a detailed overview of these issues.

Expert opinion: Infants under six months are particularly vulnerable to pertussis. Early and effective prevention strategies, such as enhanced maternal immunization and adjusted vaccination schedules, are needed. Increasing vaccine coverage and developing safer, more immunogenic vaccines are essential. Policymakers should prioritize these measures to reduce pertussis incidence and complications among infants in China.