Effectiveness of 10-valent pneumococcal conjugate vaccine against radiologically confirmed pneumonia and invasive pneumococcal disease among young children in Mozambique

BACKGROUND: Mozambique introduced the 10-valent pneumococcal conjugate vaccine (PCV10) in 2013. We aimed to assess PCV10 effectiveness against radiologically confirmed pneumonia (RCP) and invasive pneumococcal disease (IPD) among young children in southern Mozambique. METHODS: We conducted a case-control vaccine effectiveness (VE) study at 2 sites (Mavalane and Manhiça) from January 2014 to December 2016. Children age-eligible to have received PCV10 admitted with pneumonia underwent chest radiograph with standardized interpretation as per the World Health Organization and had nasopharyngeal swabs collected and cultured. IPD cases were recruited in Manhiça only, leveraging existing surveillance; IPD was defined as pneumococcus detected through blood culture or cerebrospinal fluid culture and/or PCR with serotyping by Quellung or PCR. We enrolled age-matched community controls (date of birth ±1 month for cases aged