Expert Review of Vaccines最新文献

Background: Respiratory syncytial virus (RSV) is an important cause of severe respiratory illness in older adults and adults with certain health conditions. Adjuvanted RSVPreF3 and non-adjuvanted RSVpreF vaccines were approved in 2023 for use in adults aged ≥60 years in the United States (US). This study explored the impact of RSV vaccination during the first season of vaccine availability.

Research design and methods: A Markov model was adapted to compare RSV-related outcomes in adults aged ≥60 years with or without RSV vaccination. Analyses were based on real-world RSV vaccination uptake and effectiveness in the 2023-2024 season. Scenario analyses assumed the same higher uptake as for influenza vaccines.

Results: Over 1 year, real-world RSV vaccinations were estimated to avert 18,326 RSV-related emergency department (ED) visits, 23,630 hospitalizations, and 1,930 deaths versus no vaccination. Assuming the same uptake as for influenza vaccines resulted in considerable additional RSV disease burden averted (avoiding a total of 65,740 RSV-related ED visits, 84,551 hospitalizations, and 6,838 deaths over 1 year vs. no vaccination).

Conclusions: Findings suggest that real-world RSV vaccinations have substantially reduced RSV disease burden in the US. Increasing RSV vaccination uptake among eligible adults aged ≥60 years could provide additional public health benefits.

Introduction: Varicella-zoster virus (VZV) is a highly contagious virus that manifests as varicella (chickenpox) as primary infection and reactivates as herpes zoster (HZ, shingles), with the potential for severe complications. Vaccines against varicella and HZ are available and highly effective, but recommendations vary between countries.

Areas covered: This qualitative review discusses the literature regarding (i) the burden of varicella and HZ; (ii) current approaches to vaccination against VZV-related diseases and reasons why varicella and HZ vaccination may not have been widely implemented, and (iii) real-world evidence and trends from countries with vaccination program experience.

Expert opinion: Varicella and HZ pose significant burdens. The availability of effective vaccines with established safety profiles means that prevention of both manifestations of VZV disease is now largely possible. Reasons why National Immunization Technical Advisory Groups may not recommend varicella and HZ vaccination programs include cost-effectiveness, considerations relating to the interplay of both diseases, and low awareness of the true disease burden. Nevertheless, real-world evidence from countries with existing vaccination programs is demonstrating positive impacts of vaccination on disease incidence and cost. Including both varicella and HZ vaccines in National Immunization Programs can be an effective life-course strategy to tackle the burden of VZV-related diseases.

Introduction: The World Health Organisation (WHO) introduced the Expanded Programme on Immunisation (EPI) in 1974 to reduce morbidity and mortality from a range of vaccine-preventable infectious diseases including pertussis. However, almost 50 years later pertussis infection continues to be a public-health concern in high- and low-and-middle-income countries.

Areas covered: We review: the clinical heterogeneity of disease in an immunized population and the current estimates of global disease burden; the vaccine-types currently used to prevent pertussis infection and the evidence behind the current schedules of immunization recommended by the WHO; the current understanding of the immune responses relating to protection from disease and colonization; the regional differences in routinely used schedules of immunization.

Expert opinion: The current heterogeneity of schedules and vaccines reflects uncertainty about the best strategies for long-term control of pertussis infection. Whole cell pertussis vaccines are associated with sustained population control of infection but are reactogenic; acellular pertussis vaccines are less reactogenic but do not appear to give sustained protection against transmission. Continuing to develop and apply emerging insights into the nature of the immune responses needed to provide robust protection against pertussis may enable the development of novel vaccines and optimal schedules of immunization.

Background: The paper provides a novel perspective beyond existing theoretical frameworks by integrating the COM-B model with discrete choice experiments (DCEs) to quantify parental decision-making dynamics for adolescent HPV vaccination.

Research design and methods: Two cross-sectional surveys were conducted in Wuxi, China, before and after the introduction of free domestic bivalent vaccines. Multinomial logistic regression identified COM-B predictors of vaccination intention, whereas DCEs quantified parental preferences. Latent class analysis (LCA) linked preference heterogeneity to COM-B domains with policy simulations comparing 20 vaccination scenarios.

Results: Health benefit perception (motivation), financial/temporal self-efficacy (motivation), and social influence (opportunity) are key predictors. Generally, parents prioritized HPV vaccines with low cost, high efficacy, and low side effect risks, while hesitant and refusing parents showed less concern with appointment difficulties but preference for imported producers. Five distinct HPV vaccination preference groups are identified: domestic-affordable, cost-sensitive, efficacy-focused, safety-oriented, and accessibility-driven. Hesitant and refusing parents were representative in cost-sensitive and accessibility-driven, which were sensitive in simulated incentives or convenience-enhancing scenarios. Free domestic 2-valent vaccine maintained its dominance in choice probability across simulated scenarios, except for the National Immunization Program.

Conclusions: Findings support stratified interventions targeting motivation (education, persuasion) and opportunity (cost subsidies, accessibility) based on the free domestic 2-valent vaccine policy.

Background: Influenza poses a significant global public health burden, particularly among pediatric populations. However, the coverage of influenza vaccination among Chinese children remains inadequate.

Research design and methods: This study explores the relationship between parental vaccine literacy and willingness to vaccinate their children against influenza. A cross-sectional online survey was conducted using an anonymous questionnaire. Vaccine literacy was measured by the Vaccine Health Literacy scale, and logistic regression with mediation analyses was used to identify influencing factors.

Results: Among 6,177 participants, 94.67% expressed willingness to vaccinate their children. Higher vaccine literacy, especially interactive vaccine literacy, was positively associated with willingness and mediated key predictors. Male parents (OR = 1.408, p = 0.034) with prior vaccination history (OR = 6.402, p < 0.001) were more likely to vaccinate, while those with younger age (OR = 0.959, p < 0.001) and lower education (OR = 0.587, p < 0.001) were less likely to vaccinate.

Conclusions: Our study found that parents' vaccine literacy, particularly interactive vaccine literacy, shows a potential association with their willingness to vaccinate their children against influenza. Targeted interventions aimed at improving parental vaccine literacy and addressing their vaccine hesitancy are critical for enhancing influenza vaccination coverage among children.

Introduction: Pertussis remains a public health concern despite widespread vaccination, due to waning immunity and asymptomatic transmission. The shift to acellular pertussis (aP) vaccines, aimed at reducing side effects, has changed disease dynamics, requiring ongoing evaluation.

Areas covered: We examined immunization strategies and epidemiological trends in Chile, Costa Rica, Mexico, and Panama following aP vaccine introduction. Compared vaccine coverage (VC), maternal immunization (MI), and booster strategies (BS), and explored their role in disease control, including post-COVID-19 resurgence.

Expert opinion: High aP VC and MI programs have reduced pertussis in Latin America (LATAM). However, waning immunity, uneven coverage, and disrupted surveillance pose challenges. Strengthening adolescent BS, expanding MI, and improving data systems are vital for sustained control.

Introduction: To address the cervical cancer burden globally, the World Health Organization and European Union released strategies to facilitate HPV-related cancers prevention, including cervical cancer elimination. This research assessed European country level readiness to achieve cervical cancer elimination by adhering to such strategies.

Areas covered: Readiness for cervical cancer elimination was assessed across a range of guiding questions relevant to three defined key domains: vaccination, screening, and treatment, each with two sub-domains focusing on decision making and implementation efforts. Publicly available data sources were used to inform the scoring across domains, to tier countries into either high, moderate-high, moderate-low, and low readiness archetypes.Key parameters identified associated with the high readiness archetype were high vaccination coverage rates (>70%), availability of gender neutral and catch-up vaccination, school-based vaccination availability, organized screening programs, use of HPV DNA primary screening tests, and data surveillance.

Expert opinion: Our analysis highlights significant variability in decision making and implementation of vaccination, screening, and treatment programmes across Europe. Country scores expose the need for a multifaceted approach to achieve cervical cancer elimination in Europe, encompassing solid decision making commitments, implementation of these commitments, and the ability to collect, surveil, and apply the data use accurately.

Background: The development of bivalent or multivalent vaccines offers a promising strategy for combating SARS-CoV-2 mutations.

Research design and methods: In this phase 2 trial, conducted from 1 December 2021, to 25 July 2023, 392 unvaccinated adults aged ≥18 years were randomized to receive a primary series of two doses and a booster dose of SCTV01C, a bivalent protein SARS-CoV-2 vaccine.

Results: Geometric mean titers (GMTs) of neutralizing antibodies (nAb) against live Alpha, Beta, Delta, and Omicron showed 85.4-, 100.0-, 32.1-, and 9.8-fold increase from baseline on 28 days, and 49.4-, 55.3-, 5.7-fold increase against live Alpha, Beta, and Omicron on 90 days after primary series. At Day 28 and Day 90 following the booster dose, GMTs of nAb against Beta, BA.2 and BA.5 variants showed 12.1- and 8.8-, 13.8- and 7.1-, 18.7-, and 11.9-fold of increase from baseline, respectively. Reactogenicity was generally mild, with one adverse event of special interest (AESI) and 9 ≥Grade 3 treatment-related adverse events (TRAEs); all recovered within 3 days.

Conclusions: SCTV01C, when administered as both a primary series and a booster vaccination, exhibited encouraging sustained immunogenicity against both antigen-matched and antigen-mismatched variants, with no significant safety concerns.

Clinical trial registration: www.clinicaltrials.gov identifier is NCT05148091.

Introduction: Despite extensive efforts, global influenza vaccination rates remain suboptimal, particularly among high-risk populations.

Research design and methods: We conducted a comprehensive literature search up to April 2023. Experimental studies assessing the effectiveness of interventions on influenza vaccination uptake were included, expressed as risk ratios (RR) with 95% confidence intervals (CI). Random-effects meta-analysis models were utilized for pooled estimates, with heterogeneity assessed through I². Subgroup analyses and meta-regressions were performed.

Results: This meta-analysis includes 180 studies involving 2,390,119 participants and comprehensively evaluates the effectiveness of recipient-, provider-, health system-based, and multitarget interventions. Overall, interventions significantly increased vaccination rates, with a pooled RR of 1.26 (95% CI, 1.21 to 1.32). Notably, provider-based interventions were more effective for healthcare workers (RR = 1.56; 95% CI, 1.46 to 1.66), whereas recipient-based interventions were more efficacious for pregnant women (RR = 1.42; 95% CI, 1.09 to 1.85). Multitarget strategies were the most effective among older adults (RR = 2.10; 95% CI, 1.61 to 2.72) and population under age of 18 (RR = 1.53; 95% CI, 1.23 to 1.90).

Conclusions: These findings provide critical insights for optimizing public health strategies, underscoring the need for innovative and tailored approaches to enhance global vaccination uptake.

Introduction: Fifty-eight million people worldwide are chronically infected with hepatitis C virus (HCV) and are at risk of developing cirrhosis and hepatocellular carcinoma (HCC). Direct-acting antivirals are highly effective; however, they are burdened by high costs and the unchanged risk of HCC and reinfection, making prophylactic countermeasures an urgent medical need. HCV high genetic diversity is one of the main obstacles to vaccine development. The protective role of the humoral response directed against the HCV E2 glycoprotein is well established, and broadly neutralizing antibodies play a crucial role in effective viral clearance.

Areas covered: This review explores the HCV targets and the different vaccination approaches, encompassing different expression systems, antigen selection strategies, and delivery methods, focusing on those aimed at eliciting a broad and effective humoral response. Our search criteria included the keywords 'HCV,' 'Hepatitis C,' and 'vaccine' using publicly available databases. Following the screening, 54 papers were selected.

Expert opinion: The investigation of novel vaccine platforms beyond traditional approaches is necessary. While progress has been made in this direction, continued investigations on the HCV virology, immunology, and vaccinology are essential to surmount associated obstacles, heling in the development of an HCV vaccine that can benefit the global public health.