Epidemiology Department, Epiconcept, Paris, France.
National Centre for Microbiology, National Influenza Reference Laboratory, WHO-National Influenza Centre, Institute of Health Carlos III, Madrid, Spain.
Euro Surveill. 2019 Nov;24(48). doi: 10.2807/1560-7917.ES.2019.24.48.1900604.
IntroductionInfluenza A(H3N2) clades 3C.2a and 3C.3a co-circulated in Europe in 2018/19. Immunological imprinting by first childhood influenza infection may induce future birth cohort differences in vaccine effectiveness (VE).AimThe I-MOVE multicentre primary care test-negative study assessed 2018/19 influenza A(H3N2) VE by age and genetic subgroups to explore VE by birth cohort.MethodsWe measured VE against influenza A(H3N2) and (sub)clades. We stratified VE by usual age groups (0-14, 15-64, ≥ 65-years). To assess the imprint-regulated effect of vaccine (I-REV) hypothesis, we further stratified the middle-aged group, notably including 32-54-year-olds (1964-86) sharing potential childhood imprinting to serine at haemagglutinin position 159.ResultsInfluenza A(H3N2) VE among all ages was -1% (95% confidence interval (CI): -24 to 18) and 46% (95% CI: 8-68), -26% (95% CI: -66 to 4) and 20% (95% CI: -20 to 46) among 0-14, 15-64 and ≥ 65-year-olds, respectively. Among 15-64-year-olds, VE against clades 3C.2a1b and 3C.3a was 15% (95% CI: -34 to 50) and -74% (95% CI: -259 to 16), respectively. VE was -18% (95% CI: -140 to 41), -53% (95% CI: -131 to -2) and -12% (95% CI: -74 to 28) among 15-31-year-olds (1987-2003), 32-54-year-olds (1964-86) and 55-64-year-olds (1954-63), respectively.DiscussionThe lowest 2018/19 influenza A(H3N2) VE was against clade 3C.3a and among those born 1964-86, corresponding to the I-REV hypothesis. The low influenza A(H3N2) VE in 15-64-year-olds and the public health impact of the I-REV hypothesis warrant further study.
引言
2018/19 年，甲型流感病毒（H3N2）3C.2a 和 3C.3a 亚型在欧洲同时流行。首次儿童期流感感染引起的免疫印迹可能会导致未来出生队列在疫苗有效性（VE）方面的差异。
目的
I-MOVE 多中心初级保健测试阴性研究通过年龄和遗传亚组评估了 2018/19 年甲型流感病毒（H3N2）的 VE，以探索按出生队列划分的 VE。
方法
我们测量了针对甲型流感病毒（H3N2）和（亚）簇的 VE。我们按常规年龄组（0-14 岁、15-64 岁、≥65 岁）对 VE 进行分层。为了评估疫苗的免疫印迹调节效应（I-REV）假设，我们进一步对中年组进行分层，特别是包括 32-54 岁（1964-86 年）的人群，他们可能在童年时期对血凝素位置 159 处的丝氨酸产生免疫印迹。
结果
所有年龄段的甲型流感病毒（H3N2）VE 分别为-1%（95%置信区间（CI）：-24 至 18）和 46%（95% CI：8-68）、-26%（95% CI：-66 至 4）和 20%（95% CI：-20 至 46）。0-14 岁、15-64 岁和≥65 岁组中，针对 3C.2a1b 和 3C.3a 亚群的 VE 分别为 15%（95% CI：-34 至 50）和-74%（95% CI：-259 至 16）。在 15-31 岁（1987-2003 年）、32-54 岁（1964-86 年）和 55-64 岁（1954-63 年）组中，VE 分别为-18%（95% CI：-140 至 41）、-53%（95% CI：-131 至-2）和-12%（95% CI：-74 至 28）。
讨论
最低的 2018/19 年甲型流感病毒（H3N2）VE 是针对 3C.3a 亚群和 1964-86 年出生的人群，这与 I-REV 假设相符。15-64 岁人群中较低的甲型流感病毒（H3N2）VE 和 I-REV 假设对公共卫生的影响值得进一步研究。
