National Reference Center for Streptococci, Department of Medical Microbiology, University Hospital (RWTH), Aachen, Germany.
PLoS One. 2019 Aug 1;14(8):e0220453. doi: 10.1371/journal.pone.0220453. eCollection 2019.
A general recommendation for adult pneumococcal vaccination with 23-valent polysaccharide vaccine (PPV23) for adults 60 and older has been in place in Germany since 1998, but uptake has been low. Just over a decade after the implementation of an infant pneumococcal conjugate vaccine recommendation, we examined indirect protection effects on adult invasive pneumococcal disease (IPD) in Germany.
Reported IPD cases decreased in children under two years of age from 11.09 per 100,000 in 2003-2006 to 5.94 per 100,000 in 2017/18, while in adult age groups, reported IPD cases rose across the board, most dramatically in adults 60 years of age and over, from 1.64 to 10.08 cases per 100,000. PCV13-type IPD represents 31% of all cases in this age group, the lion's share of which is due to the rapid increase of serotype 3 IPD, which, by itself, has reached 2.11 reported cases per 100,000 and makes up 21% of all IPD cases in this age group. The two vaccine formulations currently in development (PCV15 and PCV20) would increase current (PCV13) coverage by 8.5% points and 28.0% points in children, while in adults coverage would increase by 10.4% points and 21.9% points, respectively.
While original models predicted that indirect effects of childhood vaccination would suffice for adults, it seems that the herd protection effect has reached its limit, with vaccine serotypes 4, 19F, and 19A IPD persisting in adults after initial reductions, and serotype 3 IPD not showing any herd protection effect at all.
自 1998 年以来，德国一直建议 60 岁及以上成年人接种 23 价多糖疫苗（PPV23）进行常规肺炎球菌疫苗接种，但接种率一直较低。在实施婴儿肺炎球菌结合疫苗建议仅仅十多年后，我们在德国研究了对成人侵袭性肺炎球菌病（IPD）的间接保护作用。
两岁以下儿童报告的 IPD 病例从 2003-2006 年的每 100,000 人 11.09 例减少到 2017/18 年的每 100,000 人 5.94 例，而在成年年龄组中，报告的 IPD 病例则全面上升，60 岁及以上成年人的病例上升最为显著，从每 100,000 人 1.64 例上升到 10.08 例。PCV13 型 IPD 占该年龄组所有病例的 31%，其中大部分归因于血清型 3 IPD 的迅速增加，其本身的报告病例数已达到每 100,000 人 2.11 例，占该年龄组所有 IPD 病例的 21%。目前正在开发的两种疫苗制剂（PCV15 和 PCV20）将使儿童的当前（PCV13）覆盖率分别提高 8.5%和 28.0%，而成年人的覆盖率将分别提高 10.4%和 21.9%。
虽然最初的模型预测儿童疫苗接种的间接效应足以满足成年人的需求，但看来群体保护效应已经达到了极限，最初减少后，疫苗血清型 4、19F 和 19A IPD 在成年人中仍然存在，而血清型 3 IPD 根本没有显示出任何群体保护效应。
