Streptococcus pneumoniae (pneumococcus) is a major cause of disease in children, and is associated with high morbidity and mortality worldwide [1]. In 2015, invasive pneumococcal disease (IPD) was responsible for an estimated 318,000 deaths in children under 5 years of age, with most of these deaths occurring in Africa and Southeast Asia [2]. Pneumococcus causes a wide spectrum of disease, ranging from non-invasive disease such as sinusitis, acute otitis media, and conjunctivitis to more severe disease such as pneumonia, bacteremia and meningitis [3]. Data from rural Mozambique prior to the introduction of 10-valent pneumococcal conjugate vaccine (PCV10) show an invasive pneumococcal disease (IPD) incidence of 245 cases per 100,000 child-years and a case fatality proportion of approximately 14% in children aged Mozambique introduced PCV10 into the national routine infant immunization schedule in April 2013 using a 3-dose primary series at ages 2, 3 and 4 months with no booster or catch-up campaign. Coverage of three doses based on WHO-UNICEF estimates for 2014 and 2015 were 73% and 80%, respectively [18]. Using data from our ongoing population-based surveillance for IPD and cross-sectional pneumococcal carriage surveys in Manhiça, we evaluated the invasive disease potential of pneumococcal serotypes and changes in serotype distribution pre- and post-PCV10 introduction.