Effectiveness of Seasonal Influenza Vaccination in Children in Senegal During a Year of Vaccine Mismatch: A Cluster-randomized Trial
Effectiveness of Seasonal Influenza Vaccination in Children in Senegal During a Year of Vaccine Mismatch: A Cluster-randomized Trial
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DOI：
10.1093/cid/ciz066
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发表时间：
2019-11-15
影响因子：
11.8
通讯作者：
Victor, John C.
中科院分区：
文献类型：
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作者：
Diallo, Aldiouma;Diop, Ousmane M.;Victor, John C.
背景儿童接种流感疫苗的人群效应尚未得到广泛研究，特别是在热带发展中国家。在塞内加尔农村地区，我们评估了三价灭活流感疫苗（IIV 3）的总体（主要目标）和间接有效性。在这项双盲、整群随机试验中，村庄被随机分配（1：1），对6个月至10岁的儿童进行2008-09年北方半球IIV 3或灭活脊髓灰质炎疫苗（IPV）的高覆盖率疫苗接种。对接种者进行了严重不良事件监测。通过每周家访和在指定诊所进行监测，监测所有接种疫苗和未接种疫苗的村民的流感疾病体征和症状。主要结果是所有实验室确认的症状性流感。在2009年5月23日至7月11日期间，对20个村庄进行了随机化，66.5%的适龄儿童参加了研究（IIV 3村庄3 918名，IPV村庄3 848名）。随访持续至2010年5月28日。确定了4起不相关的严重不良事件。在接种疫苗者中，对季节性流感病毒（根据抗原特性数据，推测都是漂移的A/H3 N2）引起的疾病的总有效性为43.6%（95%置信区间[CI] 18.6-60.9%）。对季节性甲型H3 N2流感的间接有效率为15.4%（95%CI-22.0 ~ 41.3%）。对大流行性流感病毒（A/H1N1 pdm 09）引起的疾病的总有效率为-52.1%（95%CI-177.2 ~ 16.6%）。IIV 3为塞内加尔儿童提供了统计学上显著的中度保护，以对抗2010年前流行的季节性流感病毒株，但对A/H1N1 pdm 09没有保护作用，该疫苗不包括A/H1N1 pdm 09。没有测量到间接影响。需要在低资源人群中进行进一步研究。
Background. The population effects of influenza vaccination in children have not been extensively studied, especially in tropical, developing countries. In rural Senegal, we assessed the total (primary objective) and indirect effectiveness of a trivalent inactivated influenza vaccine (IIV3).Methods. In this double-blind, cluster-randomized trial, villages were randomly allocated (1:1) for the high-coverage vaccination of children aged 6 months through 10 years with either the 2008-09 northern hemisphere IIV3 or an inactivated polio vaccine (IPV). Vaccinees were monitored for serious adverse events. All village residents, vaccinated and unvaccinated, were monitored for signs and symptoms of influenza illness using weekly home visits and surveillance in designated clinics. The primary outcome was all laboratory-confirmed symptomatic influenza.Results. Between 23 May and 11 July 2009, 20 villages were randomized, and 66.5% of age-eligible children were enrolled (3918 in IIV3 villages and 3848 in IPV villages). Follow-up continued until 28 May 2010. There were 4 unrelated serious adverse events identified. Among vaccinees, the total effectiveness against illness caused by the seasonal influenza virus (presumed to all be drifted A/H3N2, based on antigenic characterization data) circulating at high rates among children was 43.6% (95% confidence interval [CI] 18.6-60.9%). The indirect effectiveness against seasonal A/H3N2 was 15.4% (95% CI -22.0 to 41.3%). The total effectiveness against illness caused by the pandemic influenza virus (A/H1N1pdm09) was -52.1% (95% CI -177.2 to 16.6%).Conclusions. IIV3 provided statistically significant, moderate protection to children in Senegal against circulating, pre-2010 seasonal influenza strains, but not against A/H1N1pdm09, which was not included in the vaccine. No indirect effects were measured. Further study in low-resource populations is warranted.