Expert Review of Vaccines最新文献

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.

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: 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.

Objectives: The attitudes and perceptions of healthcare consumers (HCCs) are increasingly becoming more relevant in decision-making with healthcare providers and incorporated into healthcare decision-making by national immunization technical advisory groups and health technology assessment agencies. With newer pneumococcal vaccine options available, HCCs' attitudes and perceptions play a key role in gauging potential acceptance. The objective of this study was to assess HCCs' knowledge, attitudes, and perceptions toward pneumococcal vaccines for adults.

Methods: Between March and May 2024, eligible U.S. adult HCCs were invited to participate in an online survey focusing on experiences and attitudes toward vaccines.

Results: Among 141 participating HCCs, average age was 53.1 years. The majority of participants were male (51.1%) and 64.5% identified as White. Most HCCs received at least one vaccine in the past year (81.6%). HCCs most often received vaccines at medical offices and pharmacies. HCCs supported lowering the age-based pneumococcal vaccine recommendation to all adults 50 years and older and were willing to receive a supplemental pneumococcal vaccine dose following completion of the recommended series for additional protection.

Conclusions: These findings indicate that new adult pneumococcal vaccines would be accepted and valued by HCCs if recommended by HCPs.

Background: The dynamic evolution of the virus causing COVID-19 necessitates the development of adapted vaccines to protect against emerging variants.

Research design and methods: A combined Markov-decision tree model estimated the outcomes of alternative vaccination strategies. The Saudi Arabian population was stratified into standard-risk and high-risk subpopulations, defined as either the population comprising individuals aged ≥ 65 years and individuals with at least one comorbidity. The model estimated the health and economic outcomes of vaccination based on age-specific inputs taken from published sources and national surveillance data.

Results: The vaccination strategy targeting the elderly and high-risk subpopulation (was estimated to prevent 156,694 cases 12,800 hospitalizations, and 2,919 deaths and result in cost savings of SAR 1,239 million in direct costs and SAR 4,145 million in indirect costs. These gains increased with the vaccination strategies additionally targeting other subpopulations. Compared to the base case (aged ≥65 and those at high-risk), expanding vaccination coverage to 75% of the standard-risk population prevented more cases (323%), hospitalizations (154%), and deaths (60%) and increased the direct (232%) and indirect (270%) cost savings.

Conclusions: The adoption of broad vaccination strategies using a vaccine adapted to the dominant variant in circulation would yield substantial benefits in Saudi Arabia.

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: 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.

Background: The burden of pneumococcal disease varies regionally in China, disproportionately affecting children in many provinces such as Qinghai and Hainan. Nevertheless, the absence of a pneumococcal conjugate vaccine (PCV) in the National Immunization Program (NIP) or local programs presents limited coverage. This study evaluated the health and economic impact of including PCV in immunization programs in Qinghai and Hainan.

Research design and methods: A decision tree Markov model was constructed to simulate health outcomes and lifetime costs among children under different 13-valent PCV (PCV13) vaccination strategies compared to current practices, from societal and healthcare perspectives. Data on epidemiology, vaccine efficacy, cost, and utility were obtained from the literature and open databases. Sensitivity analyses were conducted to explore parameter uncertainty.

Results: Including three-dose PCV13 in provincial programs at NIP coverage (98.91%) could avert 7100 episodes and 118 deaths in Qinghai, and 6200 episodes and 66 deaths in Hainan. It was cost-effective at the $68.2/dose in private market and cost-saving at the United Nations Children's Fund (UNICEF) recommended $25/dose for both provinces. Increasing coverage to 50% or 75% was also cost-effective. Sensitivity analyses confirmed the robustness of the results despite parameter uncertainty.

Conclusions: Prioritizing PCV13 in immunization programs in Qinghai and Hainan could effectively reduce disease burden, improve population health, and promote health equity.