Expert Review of Vaccines最新文献

Background: We aimed to estimate XBB.1.5 vaccine effectiveness (VE) against COVID-19-related hospitalizations and deaths during BA.2.86/JN.1 predominance, among EU/EEA individuals with ≥ 65-years.

Research design and methods: We linked electronic health records to create historical cohorts in Belgium, Denmark, Italy, Navarre (Spain), Norway, Portugal and Sweden. We included individuals aged ≥ 65-years eligible for the autumnal 2023 COVID-19 vaccine. Follow-up started when ≥ 80% of country-specific sequenced viruses were BA.2.86/JN.1 (4/dec/23 to 08/jan/24) and ended 25 February 2024. At study site level, we estimated the vaccine confounder-adjusted hazard ratio (aHR) of COVID-19 hospitalizations and deaths between individuals with ≥14 days after vaccination versus unvaccinated in autumn 2023, overall, by time since vaccination and age groups. VE was estimated as (1-pooled aHR)x100 with a random-effects model.

Results: XBB.1.5 VE against COVID-19 hospitalizations was 50% (95%CI: 45 to 55) and 41% (95%CI: 35 to 46) in 65-79-year-olds and in ≥ 80-year-olds respectively. VE against COVID19-related-death was 58% (95%CI: 42 to 69) and 48% (95%CI: 38 to 57), respectively, in both age groups. VE estimates against each outcome declined in all age groups over time.

Conclusion: Monovalent XBB.1.5 vaccine had a moderate protective effect against severe and fatal COVID-19 likely caused by BA.2.86/JN.1 during the 2023/2024 winter, among persons aged ≥ 65.

Introduction: Changing population demographics places a premium on optimizing older adult health. Vaccine-preventable diseases represent a substantial clinical and economic burden in older adults (≥65 years).

Areas covered: This narrative review summarizes the adult immunization landscape in three countries; Saudi Arabia, the United Arab Emirates and Türkiye, informed by literature searches; Pubmed (23-27 September 2023) supplemented by citation tracking via Google Scholar). Existing vaccination recommendations and published data were reviewed to evaluate vaccine uptake, chiefly focusing on core adult vaccines (seasonal influenza, pneumococcal and herpes zoster). Barriers to vaccine access and uptake were reviewed, and initiatives to improve recommended vaccine uptake in older (≥65 years) or otherwise high-risk adults are described.

Expert opinion: Uptake of recommended adult vaccines is low in all three countries. Receipt of annual seasonal influenza vaccine is typically below 50% in both older and at-risk younger adults; pneumococcal vaccination rates are even lower in eligible adults (<15% and often far lower), as is herpes zoster vaccine uptake (typically <5%). Low coverage is driven chiefly by low awareness of vaccine benefits, inconsistent recommendations, and vaccine hesitancy, together with often complex adult vaccine access pathways. Initiatives and remedies aimed at augmenting adult vaccination rates are warranted.

Background: To assess the immunogenicity and safety of two-dose regimen of inactivated COVID-19 vaccines in patients with pulmonary tuberculosis (PTB), and explored the potential benefits of additional dose.

Research design and methods: 182 PTB patients were randomly (1:1) assigned to the standard-dose group to receive three standard doses of inactivated COVID-19 vaccines, or the double-dose boosting group to receive two standard doses plus a double dose, with a 28-day interval. 40 healthy controls were assigned to receive two doses of inactivated COVID-19 vaccines 28 days apart. The primary endpoint was neutralizing antibodies 28 days after the second vaccination.

Results: Two doses of inactivated COVID-19 vaccines induced comparable neutralizing antibodies in PTB patients and the healthy controls, with GMTs against ancestral SARS-CoV-2 of 36.8 vs 31.4 (p = 0.4618) and seroconversion rates of 83.9% vs 87.5% (p = 0.6965). In the PTB patients, a third dose at day 56 led to a modest increase in neutralizing antibodies compared to the second dose, with a GMT fold increase of 1.3-1.8. Most adverse reactions were mild pain at the injection site.

Conclusions: Inactivated COVID-19 vaccine was safe and immunogenic in PTB patients, and two-dose immunization could induce moderate level of humoral responses similar to the healthy adults.

Clinical trials registration: www.clinicaltrials.gov identifier: NCT05148949.

Introduction: Vaccine-preventable respiratory infections (VPRI) including those caused by Streptococcus pneumoniae, influenza, respiratory syncytial virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pose substantial challenges to health and social care systems. In the UK, routine adult respiratory vaccination programs are in place. The objective of this article is to review the current evidence on the impact of four seasonal VPRIs in adults risk group definitions and to explore the strengths and limitations of current recommendations, and to identify evidence gaps for further research.

Areas covered: Relevant evidence on UK data from surveillance systems, observational studies and publicly available government documents is collated and reviewed, as well as selected global data.

Expert opinion: Disparities exist between adult risk group categories for different respiratory vaccination programs as defined in the current vaccination guidance. The burden of multiple respiratory pathogens signifies importance of routine multi-pathogen testing with the need for a resilient and large-scale national surveillance system. Further understanding of epidemiological trends and disease burden will help guide decision-making and planning of targeted strategies for disease prevention and control. Addressing inequalities in disease burden and vaccine coverage particularly in clinical risk groups, and promoting equitable vaccine access remain a priority.

Introduction: Malaria continues to remain a major global health problem with nearly a quarter of a billion clinical cases and more than 600,000 deaths in 2022. There has been significant progress toward vaccine development, however, poor efficacy of approved vaccines requiring multiple immunizing doses emphasizes the need for continued efforts toward improved vaccines. Progress to date, nonetheless, has provided impetus for malaria elimination.

Areas covered: In this review we will focus on diverse immune mechanisms targeting gametocytes in the human host and gametocyte-mediated malaria transmission via the mosquito vector.

Expert opinion: To march toward the goal of malaria elimination it will be critical to target the process of malaria transmission by mosquitoes, mediated exclusively by the sexual stages, i.e. male, and female gametocytes, ingested from infected vertebrate host. Studies over several decades have established antigens in the parasite sexual stages developing in the mosquito midgut as attractive targets for the development of transmission blocking vaccines (TBVs). Immune clearance of gametocytes in the vertebrate host can synergize with TBVs and directly aid in maintaining effective transmission reducing immune potential.