Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
NIHR Global Health Research Unit on Mucosal Pathogens, Division of Infection and Immunity, University College London, London, UK.
Nat Commun. 2020 May 6;11(1):2222. doi: 10.1038/s41467-020-15786-9.
There are concerns that pneumococcal conjugate vaccines (PCVs) in sub-Saharan Africa sub-optimally interrupt Streptococcus pneumoniae vaccine-serotype (VT) carriage and transmission. Here we assess PCV carriage using rolling, prospective nasopharyngeal carriage surveys between 2015 and 2018, 3.6-7.1 years after Malawi's 2011 PCV13 introduction. Carriage decay rate is analysed using non-linear regression. Despite evidence of reduction in VT carriage over the study period, there is high persistent residual carriage. This includes among PCV-vaccinated children 3-5-year-old (16.1% relative reduction from 19.9% to 16.7%); PCV-unvaccinated children 6-8-year-old (40.5% reduction from 26.4% to 15.7%); HIV-infected adults 18-40-years-old on antiretroviral therapy (41.4% reduction from 15.2% to 8.9%). VT carriage prevalence half-life is similar among PCV-vaccinated and PCV-unvaccinated children (3.26 and 3.34 years, respectively). Compared with high-income settings, there is high residual VT carriage 3.6-7.1 years after PCV introduction. Rigorous evaluation of strategies to augment vaccine-induced control of carriage, including alternative schedules and catch-up campaigns, is required.
人们担心在撒哈拉以南非洲地区，肺炎球菌结合疫苗（PCV）不能最佳地中断肺炎球菌疫苗血清型（VT）的携带和传播。在这里，我们评估了 2015 年至 2018 年期间使用滚动式前瞻性鼻咽携带调查的 PCV 携带情况，这是在马拉维 2011 年引入 PCV13 后的 3.6-7.1 年。使用非线性回归分析携带衰减率。尽管有证据表明在研究期间 VT 携带有所减少，但仍存在高残留携带。这包括 PCV 疫苗接种儿童 3-5 岁（从 19.9%降至 16.7%，相对减少 16.1%）；PCV 未接种儿童 6-8 岁（从 26.4%降至 15.7%，减少 40.5%）；接受抗逆转录病毒治疗的 18-40 岁 HIV 感染成年人（从 15.2%降至 8.9%，减少 41.4%）。PCV 疫苗接种和未接种儿童的 VT 携带流行半衰期相似（分别为 3.26 年和 3.34 年）。与高收入国家相比，在 PCV 引入后 3.6-7.1 年，仍存在高残留的 VT 携带。需要严格评估增强疫苗诱导的携带控制的策略，包括替代方案和补种运动。
