A pneumococcal conjugate vaccine (PCV) probe study to define the role of under-fives in within-household transmission of Streptococcus pneumoniae to infants in high disease burden settings

Streptococcus pneumoniae (the pneumococcus) is a bacterium that lives harmlessly at the back of the nose but also causes serious infections, mostly in young children. African infants are vaccinated against the pneumococcus from about two months of age but are often exposed to the pneumococcus before they are fully protected. I will use innovative technologies to study the importance of children less than 5 years old in the transmission of the pneumococcus to newborn infants living within the same household. In the context of a rigorous clinical trial, I will test whether a booster dose of the pneumococcal conjugate vaccine (PCV) given to children 1-5 years old reduces transmission and therefore protects babies living within the same household (cocooning). My Fellowship will improve our understanding of how the pneumococcus is transmitted to infants in a household-setting and will providing information to improve current vaccination policies for children.