Streptococcus pneumoniae (aka Pneumococcus), a Gram-positive, catalase-and optochin-negative diplococci bacterium, is a common aetiology of community acquired pneumonia – a condition that caused over 0.8 million deaths of children under 5 years old in 2017.

Since 2014, Vietnam has introduced PCV10 as an optional vaccine. It is important to gather local research-based evidence, that investigates the circulation of commensal and pathogenic pneumococcus after the (optional) PCV vaccine was launched in Vietnam, to start evaluating the coverage of vaccine in Vietnam as well as to evaluate the impact of vaccine on the circulation of serotypes of S. pneumoniae in Vietnam.

This study investigates the serotype distribution of nasal pharyngeal carriage and disease- associated S. pneumoniae isolated from non-vaccinated and vaccinated healthy infants as well as children with community-acquired pneumonia.