WHO position paper,Meningococcal A conjugate vaccine: Updated guidance,February 2015

This article presents the World Health Organization’s (WHO) updated recommendations on the use of meningococcal vaccines excerpted from the WHO position paper on Meningococcal A conjugate vaccine: updated guidance, February 2015, published in the Weekly Epidemiological Record [1].A position paper on meningococcal vaccines was published in 2011 and its recommendations remain valid [2]. This update adds to the previous recommendations specifically concerning routine immunization of infants and young children in the African meningitis belt with meningococcal A conjugate vaccine.Footnotes to this paper provide a number of core references including references to grading tables that assess the quality of the scientific evidence. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO's current position on the use of vaccines in the global context. Recommendations on the use of the Meningococcal A conjugate vaccine were discussed by SAGE in October 2014; evidence presented at these meetings can be accessed at: http://www.who.int/immunization/sage/meetings/2014/october/presentations_background_docs/en/.     

Hemagglutinin-specific CD4+ T-cell responses following 2009-pH1N1 inactivated split-vaccine inoculation in humans

Influenza A virus remains a major threat to public health, and the inactivated split-virus vaccine is the most prevalent vaccine used worldwide. However, our knowledge about cellular immune responses to the inactivated influenza virus vaccine and its correlation with humoral responses are yet limited, which has restricted our understanding of the vaccine’s protective mechanisms. Herein, in two clinical trials, T-cell responses specific for both previously identified human leucocyte antigen (HLA)-I-restricted epitopes from influenza virus and hemagglutinin (HA) protein were longitudinally investigated before, during, and after a two-dose vaccination with the inactivated 2009 pandemic H1N1 (2009-pH1N1) vaccine. A robust antibody response in all of the donors after vaccination was observed. Though no CD8⁺ T-cell responses to known epitopes were detected, HA-specific T-cell responses were primed following vaccination, and the responses were found to be mainly CD4⁺ T-cell dependent. However, HA-specific T-cells circulating in peripheral blood dropped to baseline levels 6 weeks after vaccination, but humoral immune responses maintained a high level for 4 months post-vaccination. Significant correlations between the magnitude of the HA-specific T-cell responses and hemagglutination inhibition antibody titers were demonstrated, indicating a priming role of HA-specific T-cells for humoral immune responses.In conclusion, our study indicates that HA-specific CD4⁺ T-cell responses can be primed by the inactivated 2009-pH1N1 vaccine, which may coordinate with the elicitation of antibody protection. These findings would benefit a better understanding of the immune protective mechanisms of the widely used inactivated 2009-pH1N1 vaccine.     

Association of female reproductive and hormonal factors with gallbladder cancer risk in Asia: A pooled analysis of the Asia Cohort Consortium

The female predominance of gallbladder cancer (GBC) has led to a hypothesis regarding the hormone-related aetiology of GBC. We aimed to investigate the association between female reproductive factors and GBC risk, considering birth cohorts of Asian women. We conducted a pooled analysis of 331,323 women from 12 cohorts across 4 countries (China, Japan, Korea, and Singapore) in the Asia Cohort Consortium. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) to assess the association between reproductive factors (age at menarche, parity, age at first delivery, breastfeeding, and age at menopause) and GBC risk. We observed that a later age at menarche was associated with an increased risk of GBC (HR 1.4, 95% CI 1.16–1.70 for 17 years and older vs. 13–14 years), especially among the cohort born in 1940 and later (HR 2.5, 95% CI 1.50–4.35). Among the cohort born before 1940, women with a later age at first delivery showed an increased risk of GBC (HR 1.56, 95% CI 1.08–2.24 for 31 years of age and older vs. 20 years of age and younger). Other reproductive factors did not show a clear association with GBC risk. Later ages at menarche and at first delivery were associated with a higher risk of GBC, and these associations varied by birth cohort.     

Immunology: Paper alert

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology.     

中国65岁及以上老年人睡眠时长对认知障碍影响的队列研究

目的:探讨我国老年人睡眠时长对认知障碍发生风险的影响。方法:将2005年中国老年健康影响因素跟踪调查招募的9 679名认知完好老年人的调查信息作为基线数据,随访该队列人群至2018年,采用Cox比例风险回归模型分析老年人的不同睡眠时长与其认知障碍发生风险的关联。结果:与睡眠时长为6 h的老年人比较,睡眠时长≤5 h的老...     

Pertussis vaccination in a cohort of older Australian adults following a cocooning vaccination program

BackgroundWhile recommendations to vaccinate adults against pertussis exist, information on uptake for adult tetanus-diphtheria-pertussis vaccine (Tdap) among older adults is limited.MethodsWe used data from the 45 and Up Study, a prospective cohort of adults aged ≥45 years who completed a questionnaire between 2012 and 2014 asking about pertussis vaccination. We evaluated Tdap uptake following a program providing free vaccine for adults in contact with young children between 2009 and 2012.ResultsAmong 91,432 adults (mean age = 66.3 years, SD = 9.6), 3.1% (n = 2823) reported receiving Tdap prior to the program. This increased seven-fold to 21.8% (n = 19898) after the program finished. Tdap coverage was almost twice as high in women compared to men and among adults more likely to be grandparents than those not.ConclusionThese findings suggest that funding for a targeted program can help to substantially increase vaccination coverage as well as decrease disparities in the uptake of Tdap in different sub-groups.