Immunisation, Hepatitis, and Blood Safety Department, Health Protection Services, Public Health England, London, UK.
Statistics, Modelling, and Economics Department, Health Protection Services, Public Health England, London, UK.
Lancet Infect Dis. 2015 May;15(5):535-43. doi: 10.1016/S1473-3099(15)70044-7. Epub 2015 Mar 20.
The 13-valent pneumococcal conjugate vaccine (PCV13) protects against key serotypes that increased after routine immunisation with the seven-valent vaccine (PCV7), but its potential for herd protection and serotype replacement is uncertain. The aim of this study was to analyse the effect of the 13-valent pneumococcal conjugate vaccine on invasive pneumococcal disease in England and Wales 4 years after its introduction.
We used a national dataset of electronically reported and serotyped invasive pneumococcal disease cases in England and Wales to estimate incidence rate ratios (IRRs) for vaccine and non-vaccine type invasive pneumococcal disease between July, 2013, and June, 2014, versus the pre-PCV13 and pre-PCV7 baseline. Incidence rates were corrected for missing serotype data and changes in surveillance sensitivity over time. An over-dispersed Poisson model was used to estimate IRRs and confidence intervals.
Incidence of invasive pneumococcal disease in the epidemiological year 2013/14 decreased by 32% compared with the pre-PCV13 baseline (incidence 10·14 per 100,000 in 2008-10 vs 6·85 per 100,000 in 2013/14; IRR 0·68, 95% CI 0·64-0·72). This was due to an 86% reduction of the serotypes covered by PCV7 (1·46 vs 0·20 per 100,000; IRR 0·14, 0·10-0·18) and a 69% reduction of the additional six serotypes covered by PCV13 (4·48 vs 1·40 per 100,000; IRR 0·31, 0·28-0·35). When compared with the pre-PCV7 baseline, there was a 56% overall reduction in invasive pneumococcal disease (15·63 vs 6·85 per 100,000; IRR 0·44, 95% CI 0·43-0·47). Compared with the pre-PCV13 baseline, the incidence of non-PCV13 serotypes increased (incidence all ages 4·19 vs 5·25 per 100,000; IRR 1·25, 95% CI 1·17-1·35) due to increases across a broad range of serotypes in children younger than 5 years and in people aged 45 years or more. In children younger than 5 years, incidence of non-PCV13 serotypes in 2013/14 was higher than in 2012/13 (age <2 years: 12·03 vs 10·83 per 100,000; age 2-4 years: 4·08 vs 3·63 per 100,000).
8 years of PCV use in England and Wales has reduced the overall incidence of invasive pneumococcal disease by more than 50%. The herd protection induced by PCV7 is continuing, and similar indirect protection is occurring from the additional serotypes covered by PCV13. There is, however, evidence of increasing invasive pneumococcal disease due to non-PCV13 serotypes, particularly in children younger than 5 years in 2014. If this increase continues, the maximum benefit of the PCV13 programme in children might already have been achieved.
Public Health England funds national surveillance of invasive pneumococcal disease.
13 价肺炎球菌结合疫苗（PCV13）可预防 7 价肺炎球菌结合疫苗（PCV7）常规免疫后增加的关键血清型，但它的群体保护和血清型替代作用尚不确定。本研究旨在分析 13 价肺炎球菌结合疫苗在引入后 4 年内对英格兰和威尔士侵袭性肺炎球菌病的影响。
我们使用了英格兰和威尔士电子报告和血清型侵袭性肺炎球菌病病例的国家数据集，以估计 2013 年 7 月至 2014 年 6 月期间疫苗和非疫苗型侵袭性肺炎球菌病的发病率比值（IRR），与 PCV13 和 PCV7 基线前相比。发病率对缺失血清型数据和随时间变化的监测敏感性进行了校正。使用过度分散泊松模型估计 IRR 和置信区间。
2013/14 年流行病学年侵袭性肺炎球菌病的发病率与 PCV13 基线前相比下降了 32%（2008-10 年每 10 万人中有 10.14 例，2013/14 年每 10 万人中有 6.85 例；IRR 0.68，95%CI 0.64-0.72）。这是由于 PCV7 涵盖的血清型减少了 86%（1.46 比每 100,000 人 0.20；IRR 0.14，0.10-0.18），PCV13 额外涵盖的 6 种血清型减少了 69%（4.48 比每 100,000 人 1.40；IRR 0.31，0.28-0.35）。与 PCV7 基线前相比，侵袭性肺炎球菌病总体减少了 56%（15.63 比每 100,000 人 6.85；IRR 0.44，95%CI 0.43-0.47）。与 PCV13 基线前相比，非 PCV13 血清型的发病率增加（所有年龄组为 4.19 比每 100,000 人 5.25；IRR 1.25，95%CI 1.17-1.35），这是由于 5 岁以下儿童和 45 岁及以上人群中广泛的血清型增加所致。在 5 岁以下儿童中，2013/14 年非 PCV13 血清型的发病率高于 2012/13 年（<2 岁年龄组：每 100,000 人 12.03 比 10.83；2-4 岁年龄组：每 100,000 人 4.08 比 3.63）。
英格兰和威尔士使用 8 年 PCV 后，侵袭性肺炎球菌病的总发病率下降了 50%以上。PCV7 诱导的群体保护作用仍在继续，PCV13 额外涵盖的血清型也产生了类似的间接保护作用。然而，有证据表明，非 PCV13 血清型的侵袭性肺炎球菌病正在增加，特别是在 2014 年 5 岁以下的儿童中。如果这种增加持续下去，PCV13 方案在儿童中的最大益处可能已经实现。
英国公共卫生署为侵袭性肺炎球菌病的国家监测提供资金。
