Bar-Zeev N, Swarthout TD, Everett DB, et al. - Researchers sought to determine how Malawi's introduction of the 13-valent PCV (PCV13) in 2011 has affected vaccine and non-vaccine serotype invasive pneumococcal disease among vaccine-eligible-age and vaccine-ineligible-age children and adults. In this prospective observational time-series analysis and a case-control study, data from laboratory-based surveillance at a government hospital in Malawi were used. Six years before and 7 years after introduction of PCV13 was the included period. A total of 10,281,476 person-years of observation were included in the surveillance, with 140,498 blood and 63,291 cerebrospinal fluid cultures. Significant pre-vaccine reductions in the incidence of invasive pneumococcal disease were recorded in this high-mortality, high-HIV-prevalence setting in Africa. Although there was significant vaccine-attributable impact among vaccine-eligible-age children 7 years after PCV introduction, indirect effects benefitting unvaccinated infants and adults were not marked. They recommend considering multiple alternative strategies in policy decisions for reducing disease burden, including targeted vaccination outside the infant Expanded Programme of Immunization to benefit vulnerable populations.