Department of Paediatrics and Adolescent Medicine, Turku University Hospital and University of Turku, Turku, Finland.
Department of Virology, University of Turku, Turku, Finland.
J Microbiol Immunol Infect. 2019 Aug;52(4):526-533. doi: 10.1016/j.jmii.2017.10.007. Epub 2017 Dec 7.
BACKGROUND/PURPOSE: Influenza vaccine has been recommended in Finland since 2007 for all children of 6-35 months of age and in 2009 for those ≥6 months against pandemic influenza. We investigated the incidence of influenza and vaccine effectiveness in a birth cohort of children in 2008-2011.
We followed 923 children from birth to 2 years of age for respiratory tract infections. A nasal swab sample for PCR for influenza A and B viruses was taken at the onset of acute respiratory infections. Samples were collected either at the study clinic or at home by parents. Vaccination data was retrieved from the health registries.
Vaccination coverage of children aged 6-23 months was 22-47% against seasonal influenza and 80% against the A(H1N1)pdm09 virus in the pandemic season 2009-2010. During 3 influenza seasons, 1607 nasal swab samples were collected. Influenza was confirmed in 56 (6.1%) of 923 children (16 A(H1N1), 14 A(H3N2), and 26 B viruses). The incidence of influenza was 5.1% in 2008-2009, 2.7% in 2009-2010, and 5.0% in 2010-2011. Effectiveness of the adjuvanted vaccine against the pandemic influenza A(H1N1)pdm09 was 97% (95% confidence interval, 76-100%). Three children with influenza were hospitalized.
The yearly incidence of seasonal influenza was 5% in this cohort of very young children with variable influenza vaccine coverage. Adjuvanted vaccine against the pandemic influenza was highly effective. Both seasonal and pandemic influenza cases were mostly non-severe.
背景/目的：自 2007 年以来，芬兰已建议为所有 6-35 月龄的儿童接种流感疫苗，并于 2009 年建议为所有≥6 月龄的儿童接种针对大流行性流感的疫苗。我们调查了 2008-2011 年期间出生队列儿童的流感发病率和疫苗有效性。
我们对 923 名从出生到 2 岁的儿童进行了呼吸道感染监测。在急性呼吸道感染发作时，采集鼻拭子样本进行流感 A 和 B 病毒的 PCR 检测。样本可以在研究诊所或由父母在家采集。疫苗接种数据从健康记录中获取。
2009-2010 年大流行季节，6-23 月龄儿童季节性流感疫苗接种覆盖率为 22-47%，针对 A(H1N1)pdm09 病毒的疫苗接种覆盖率为 80%。在 3 个流感季节中，共采集了 1607 份鼻拭子样本。923 例儿童中确诊流感 56 例（16 例 A(H1N1)、14 例 A(H3N2)和 26 例 B 病毒）。2008-2009 年、2009-2010 年和 2010-2011 年流感发病率分别为 5.1%、2.7%和 5.0%。含佐剂疫苗对大流行流感 A(H1N1)pdm09 的有效性为 97%（95%置信区间，76-100%）。3 例流感患儿住院。
在这个年幼儿童队列中，每年季节性流感的发病率为 5%，流感疫苗接种率存在差异。含佐剂疫苗对大流行流感高度有效。季节性和大流行性流感病例大多不严重。
