Temporal Changes in Pneumococcal Colonization in HIV-infected and HIV-uninfected Mother-Child Pairs Following Transitioning From 7-valent to 13-valent Pneumococcal Conjugate Vaccine, Soweto, South Africa

Background. We investigated the impact of infant pneumococcal conjugate vaccine (PCV) immunization on pneumococcal colonization among human immunodeficiency virus (HIV)-infected and HIV-uninfected mother-child pairs. Methods. Pneumococcal colonization was assessed in May 2010-February 2011 (period 1; 7-valent PCV era) and May 2012-April 2013 (period 2; 13-valent PCV era). Standard microbiological methods were used for pneumococcus isolation and serotyping. Results. In children 0-12 years, PCV13-serotype colonization decreased from period 1 to period 2 among HIV-uninfected (adjusted odds ratio [OR], 0.32; 95% confidence interval [CI],.25-.40) and HIV-infected children (adjusted OR, 0.37; 95% CI,.28-.49), while there was an increase in nonvaccine serotype colonization. Decreases in PCV13-serotype colonization were observed in HIV-uninfected women (adjusted OR, 0.44; 95% CI,.23-.81), with a similar trend in HIV-infected women. HIV-infected compared to -uninfected women had higher prevalence of overall (20.5% vs 9.7% in period 1; 13.8% vs 9.7% in period 2) and PCV13-serotype colonization (8.7% vs 5.4% in period 1; 4.8% vs 2.0% in period 2), P <.04 for all observations. Conclusions. Targeted PCV vaccination of African infants in a setting with high HIV prevalence was associated with PCV13-serotype colonization reduction, including among unvaccinated HIV-infected women.