School of Public Health and Community Medicine, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia; National Centre for Immunisation Research and Surveillance, Westmead, NSW, Australia.
School of Public Health and Community Medicine, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia.
Vaccine. 2018 May 3;36(19):2650-2656. doi: 10.1016/j.vaccine.2018.03.058. Epub 2018 Apr 5.
Most studies use indirect cohort or case-control methods to estimate vaccine effectiveness (VE) of 7- and 13-valent pneumococcal conjugate vaccines (PCV7 and PCV13) against invasive pneumococcal disease (IPD). Neither method can measure the benefit vaccination programs afford the unvaccinated and many studies were unable to estimate dose-specific VE. We linked Australia's national immunisation register with health data from two states to calculate IPD incidence by vaccination status and VE for a 3 + 0 PCV schedule (doses at 2, 4, 6 months, no booster) among a cohort of 1.4 million births.
Births records for 2001-2012 were probabilistically linked to IPD notifications, hospitalisations, deaths, and vaccination history (available until December 2013). IPD rates in vaccinated and unvaccinated children <2 years old were compared using Cox proportional hazards models (adjusting for potential confounders), with VE = (1 - adjusted hazard ratio) × 100. Separate models were performed for all-cause, PCV7, PCV13 and PCV13-non-PCV7 serotype-specific IPD, and for Aboriginal and non-Aboriginal children.
Following introduction of universal PCV7 in 2005, rates of PCV7 serotype and all-cause IPD in unvaccinated children declined 89.5% and 61.4%, respectively, to be similar to rates in vaccinated children. Among non-Aboriginal children, VEs for 3 doses were 94.2% (95%CI: 81.9-98.1) for PCV7 serotype-specific IPD, 85.6% (95%CI: 60.5-94.8) for PCV13-non-PCV7 serotype-specific IPD and 80.1% (95%CI: 59.4-90.3) for all-cause IPD. There were no statistically significant differences between the VEs for 3 doses and for 1 or 2 doses against PCV13 and PCV13-non-PCV7 serotype-specific IPD, or between Aboriginal and non-Aboriginal children.
Our population-based cohort study demonstrates that >90% coverage in the first year of a universal 3 + 0 PCV program provided high population-level protection, predominantly attributable to strong herd effects. The size of the cohort enabled calculation of robust dose-specific VE estimates for important population sub-groups relevant to vaccination policies internationally.
大多数研究采用间接队列或病例对照方法来估计 7 价和 13 价肺炎球菌结合疫苗（PCV7 和 PCV13）对侵袭性肺炎球菌病（IPD）的疫苗有效性（VE）。这两种方法都不能衡量疫苗接种计划为未接种人群带来的益处，并且许多研究无法估计剂量特异性 VE。我们将澳大利亚国家免疫登记处与两个州的健康数据相关联，以计算在一个 140 万例出生队列中，按照 3+0 PCV 计划（2、4、6 个月时接种 3 剂，无加强剂）接种疫苗的人群中的 IPD 发病率和 VE（截至 2013 年 12 月可获得疫苗接种史）。
2001-2012 年的出生记录与 IPD 通知、住院、死亡和疫苗接种史（直至 2013 年 12 月）进行了概率性关联。使用 Cox 比例风险模型比较 2 岁以下接种和未接种儿童的 IPD 发生率（调整了潜在混杂因素），VE=（1-调整后的风险比）×100。对于全因、PCV7、PCV13 和 PCV13-非 PCV7 血清型特异性 IPD，以及对于原住民和非原住民儿童，分别进行了单独的模型。
在 2005 年普遍接种 PCV7 后，未接种儿童的 PCV7 血清型和全因 IPD 发病率分别下降了 89.5%和 61.4%，与接种儿童的发病率相似。在非原住民儿童中，3 剂的 VE 分别为 94.2%（95%CI：81.9-98.1）、85.6%（95%CI：60.5-94.8）和 80.1%（95%CI：59.4-90.3），用于 PCV7 血清型特异性 IPD、PCV13-非 PCV7 血清型特异性 IPD 和全因 IPD。3 剂和 1 剂或 2 剂接种 PCV13 和 PCV13-非 PCV7 血清型特异性 IPD 的 VE 之间以及原住民和非原住民儿童之间没有统计学上的显著差异。
我们的基于人群的队列研究表明，在普遍实施 3+0 PCV 计划的第一年达到 90%以上的覆盖率，为人群提供了高度的保护，主要归因于强大的群体效应。该队列的规模使我们能够计算出具有国际疫苗接种政策相关性的重要人群亚组的稳健剂量特异性 VE 估计值。
