Abstract:
We present England 2021/22 end-of-season adjusted vaccine effectiveness (aVE) against laboratory confirmed influenza related emergency care use in children aged 1-17 and in adults aged 50+, and serological findings in vaccinated vs unvaccinated adults by hemagglutination inhibition assay. Influenza vaccination has been routinely offered to all children aged 2-10 years and adults aged 65 years + in England. In 2021/22, the offer was extended to children to age 15 years, and adults aged 50-64 years. Influenza activity rose during the latter half of the 2021/22 season, while remaining comparatively low due to COVID-19 pandemic control measures. Influenza A(H3N2) strains predominated. A test negative design was used to estimate aVE by vaccine type. Cases and controls were identified within a sentinel laboratory surveillance system. Vaccine histories were obtained from the National Immunisation Management Service (NIMS), an influenza and COVID-19 vaccine registry. These were linked to emergency department presentations (excluding accidents) with respiratory swabbing ≤ 14 days before or ≤ 7 days after presentation. Amongst adults, 423 positive and 32,917 negative samples were eligible for inclusion, and 145 positive and 6,438 negative samples among children. Those admitted to hospital were further identified. In serology against the circulating A(H3N2) A/Bangladesh/4005/2020-like strain, 61 % of current season adult vaccinees had titres ≥ 1:40 compared to 17 % of those unvaccinated in 2020/21 or 2021/22 (p < 0.001). We found good protection from influenza vaccination against influenza requiring emergency care in children (72.7 % [95 % CI 52.7, 84.3 %]) and modest effectiveness in adults (26.1 % [95 % CI 4.5, 42.8 %]). Adult VE was higher for A(H1N1) (81 % [95 % CI 50, 93 %]) than A(H3N2) (33 % [95 % CI 6, 53 %]). Consistent protection was observable across preschool, primary and secondary school aged children. Imperfect test specificity combined with very low prevalence may have biased estimates towards null. With limited influenza circulation, the study could not determine differences by vaccine types.
摘要:
我们介绍了英格兰2021/22季末调整疫苗有效性(AVE),针对1-17岁儿童和50岁以上成人的实验室确认流感相关紧急护理使用,以及通过血凝抑制试验在接种疫苗和未接种疫苗的成年人中的血清学发现。在英格兰,所有2-10岁的儿童和65岁以上的成年人都常规接种流感疫苗。在2021/22年度,该优惠扩大到15岁以下的儿童,和50-64岁的成年人。在2021/22赛季的后半段,流感活动有所上升,而由于COVID-19大流行控制措施,保持相对较低的水平。甲型流感(H3N2)菌株占主导地位。使用测试阴性设计来估计按疫苗类型的AVE。在前哨实验室监测系统中确定了病例和对照。疫苗史是从国家免疫管理局(NIMS)获得的,流感和COVID-19疫苗登记。这些与急诊科就诊(不包括事故)相关,就诊前≤14天或就诊后≤7天的呼吸拭子。在成年人中,423个阳性和32,917个阴性样本符合纳入条件,145个阳性样本和6,438个阴性样本。那些入院的人被进一步确认。在针对循环A(H3N2)A/孟加拉国/4005/2020样菌株的血清学中,61%的当前季节成年疫苗接种者的滴度≥1:40,而2020/21或2021/22年未接种疫苗的人为17%(p<0.001)。我们发现,在需要紧急护理的儿童中,针对流感的流感疫苗接种具有良好的保护作用(72.7%[95%CI52.7,84.3%]),在成人中效果不大(26.1%[95%CI4.5,42.8%])。A(H1N1)的成人VE(81%[95%CI50,93%])高于A(H3N2)(33%[95%CI6,53%])。在整个幼儿园都可以观察到一致的保护,中小学生。不完美的测试特异性加上非常低的患病率可能会使估计值偏向于null。由于流感循环有限,该研究无法确定疫苗类型的差异。