Buchan Sarah A, Chung Hannah, Campitelli Michael A, Crowcroft Natasha S, Gubbay Jonathan B, Karnauchow Timothy, Katz Kevin, McGeer Allison J, McNally J Dayre, Richardson David, Richardson Susan E, Rosella Laura C, Simor Andrew, Smieja Marek, Tran Dat, Zahariadis George, Kwong Jeffrey C
Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
PLoS One. 2017 Nov 17;12(11):e0187834. doi: 10.1371/journal.pone.0187834. eCollection 2017.
Uncertainty remains regarding the magnitude of effectiveness of influenza vaccines for preventing serious outcomes, especially among young children. We estimated vaccine effectiveness (VE) against laboratory-confirmed influenza hospitalizations among children aged 6-59 months. We used the test-negative design in hospitalized children in Ontario, Canada during the 2010-11 to 2013-14 influenza seasons. We used logistic regression models adjusted for age, season, and time within season to calculate VE estimates by vaccination status (full vs. partial), age group, and influenza season. We also assessed VE incorporating prior history of influenza vaccination. We included specimens from 9,982 patient hospitalization episodes over four seasons, with 12.8% testing positive for influenza. We observed variation in VE by vaccination status, age group, and influenza season. For the four seasons combined, VE was 60% (95%CI, 44%-72%) for full vaccination and 39% (95%CI, 17%-56%) for partial vaccination. VE for full vaccination was 67% (95%CI, 48%-79%) for children aged 24-59 months, 48% (95%CI, 12%-69%) for children aged 6-23 months, 77% (95%CI, 47%-90%) for 2010-11, 59% (95%CI, 13%-81%) for 2011-12, 33% (95%CI, -18% to 62%) for 2012-13, and 72% (95%CI, 42%-86%) for 2013-14. VE in children aged 24-59 months appeared similar between those vaccinated in both the current and previous seasons and those vaccinated in the current season only, with the exception of 2012-13, when VE was lower for those vaccinated in the current season only. Influenza vaccination is effective in preventing pediatric laboratory-confirmed influenza hospitalizations during most seasons.
流感疫苗预防严重后果的有效性程度仍不确定，尤其是在幼儿中。我们估计了6至59个月大儿童针对实验室确诊的流感住院病例的疫苗有效性（VE）。我们在2010 - 11年至2013 - 14年流感季节期间，对加拿大安大略省住院儿童采用了检测阴性设计。我们使用了根据年龄、季节和季节内时间进行调整的逻辑回归模型，以按疫苗接种状态（全程接种与部分接种）、年龄组和流感季节计算VE估计值。我们还评估了纳入流感疫苗接种既往史的VE。我们纳入了四个季节中9982例患者住院病例的样本，其中12.8%的样本流感检测呈阳性。我们观察到VE在疫苗接种状态、年龄组和流感季节方面存在差异。四个季节综合来看，全程接种的VE为60%（95%置信区间，44% - 72%），部分接种的VE为39%（95%置信区间，17% - 56%）。24至59个月大儿童全程接种的VE，2010 - 11年为77%（95%置信区间，47% - 90%），2011 - 12年为59%（95%置信区间，13% - 81%），2012 - 13年为33%（95%置信区间， - 18%至62%），2013 - 14年为72%（95%置信区间，42% - 86%）。24至59个月大儿童中，在当前季节和上一季节均接种疫苗的儿童与仅在当前季节接种疫苗的儿童之间，VE似乎相似，但2012 - 13年除外，当时仅在当前季节接种疫苗的儿童VE较低。流感疫苗在大多数季节对预防儿童实验室确诊的流感住院病例有效。
