South Africa Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa; Department of Science/ National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa.
South Africa Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa; Department of Science/ National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Faculty of Health Science, Johannesburg, South Africa.
Int J Infect Dis. 2023 Sep;134:45-52. doi: 10.1016/j.ijid.2023.05.016. Epub 2023 May 19.
Pneumococcal conjugate vaccines (PCVs) reduce pneumococcal-associated disease by reducing vaccine-serotype (VT) acquisition in vaccinated children, thereby interrupting VT transmission. The 7-valent-PCV was introduced in the South African immunization program in 2009 (13-valent-PCV since 2011) using a 2+1 schedule (at 6, 14, and 40 weeks of age). We aimed to evaluate temporal changes in VT and non-vaccine-serotype (NVT) colonization after 9 years of childhood PCV immunization in South Africa.
Nasopharyngeal swabs were collected from healthy children <60-month-old (n = 571) in 2018 (period-2) and compared with samples (n = 1135) collected during early PCV7-introduction (period-1, 2010-11) in an urban low-income setting (Soweto). Pneumococci were tested for using a multiplex quantitative-polymerase chain reaction serotyping reaction-set.
Overall pneumococcal colonization in period-2 (49.4%; 282/571) was 27.5% lower than period-1 (68.1%; 773/1135; adjusted odds ratio [aOR]: 0.66; 95% confidence interval [CI]: 0.54-0.88). Colonization by VT was reduced by 54.5% in period-2 (18.6%; 106/571) compared with period-1 (40.9%; 465/1135; aOR: 0.41; 95% CI: 0.3-0.56). Nevertheless, serotype 19F carriage prevalence was higher (8.1%; 46/571) in period-2 compared with period-1 (6.6%; 75/1135; aOR: 2.0; 95% CI: 1.09-3.56). NVT colonization prevalence was similar in period-2 and period-1 (37.8%; 216/571 and 42.4%; 481/1135).
There remains a high residual prevalence of VT, particularly 19F, colonization nine years post-introduction of PCV in the South African childhood immunization program.
肺炎球菌结合疫苗（PCV）通过减少接种儿童中疫苗型（VT）的获得，从而阻断 VT 传播，从而降低肺炎球菌相关疾病的发生。南非免疫计划于 2009 年（2011 年起使用 13 价 PCV）引入 7 价 PCV，采用 2+1 接种程序（6、14 和 40 周龄）。我们旨在评估南非儿童接种 PCV9 年后 VT 和非疫苗型（NVT）定植的时间变化。
2018 年（第 2 期），从 <60 月龄的健康儿童中采集鼻咽拭子（n=571），并与在城市低收入地区（索韦托）进行的早期 7 价 PCV 引入期间（第 1 期，2010-11 年）采集的样本（n=1135）进行比较。使用多重定量聚合酶链反应血清分型反应集检测肺炎球菌。
第 2 期总体肺炎球菌定植率（49.4%，282/571）比第 1 期（68.1%，773/1135）低 27.5%（调整后的优势比[OR]：0.66；95%置信区间[CI]：0.54-0.88）。第 2 期 VT 定植率下降 54.5%（18.6%，106/571），而第 1 期（40.9%，465/1135；OR：0.41；95% CI：0.3-0.56）。然而，第 2 期血清型 19F 携带率（8.1%，46/571）高于第 1 期（6.6%，75/1135；OR：2.0；95% CI：1.09-3.56）。第 2 期和第 1 期 NVT 定植率相似（37.8%，216/571 和 42.4%，481/1135）。
南非儿童免疫计划中 PCV 引入 9 年后，VT，特别是 19F，的定植仍然很高。
