摘要：SummaryBackground The 13-valent pneumococcal conjugate vaccine (PCV13) was designed to include disease-causing serotypes that are important in low-income and middle-income countries. Vaccine effectiveness estimates are scarce in these settings. South Africa replaced {PCV7} with {PCV13} in 2011 using a 2 + 1 schedule. We aimed to assess the effectiveness of two or more doses of {PCV13} against invasive pneumococcal disease in children with {HIV} infection and in those not infected with HIV. Methods Cases of invasive pneumococcal disease in children aged 5 years or younger were identified through national laboratory-based surveillance. Isolates were serotyped with the Quellung reaction or PCR. We sought in-hospital controls for every case, matched for age, {HIV} status, and study site. We aimed to enrol four controls for every case not infected with {HIV} and six controls for every case with {HIV} infection (case-control sets). With conditional logistic regression, we calculated vaccine effectiveness as a percentage, with the equation 1 – [adjusted odds ratio for vaccination] × 100. We included data from an earlier investigation of {PCV7} to assess vaccine effectiveness in children exposed to but not infected with {HIV} and in malnourished children not infected with HIV. Findings Between January, 2012, and December, 2014, we enrolled children aged 16 weeks or older to our study: 240 were cases not infected with HIV, 75 were cases with {HIV} infection, 1118 were controls not infected with HIV, and 283 were controls with {HIV} infection. The effectiveness of two or more doses of {PCV13} against PCV13-serotype invasive pneumococcal disease was 85% (95% {CI} 37 to 96) among 11 case-control sets of children not infected with {HIV} and 91% (−35 to 100) among three case-control sets of children with {HIV} infection. {PCV13} effectiveness among 26 case-control sets of children not infected with {HIV} was 52% (95% {CI} −12 to 79) against all-serotype invasive pneumococcal disease and 94% (44 to 100) for serotype 19A. Vaccine effectiveness against PCV7-serotype invasive pneumococcal disease was 87% (95% {CI} 38 to 97) in children exposed to {HIV} but uninfected and 90% (53 to 98) in malnourished children not infected with HIV. Interpretation Our results indicate that {PCV13} in a 2 + 1 schedule is effective for preventing vaccine-type pneumococcal infections in young children not infected with HIV, including those who are malnourished or who have been exposed to HIV. Although the point estimate for {PCV13} vaccine effectiveness in children infected with {HIV} was high, it did not reach significance, possibly because of the small sample size. These findings support recommendations for widespread use of pneumococcal conjugate vaccine in low-income and middle-income countries. Funding Gavi, The Vaccine Alliance.
