Mothers will be randomized to one of three arms and will receive PCV-10, PPV-23, or placebo in a blinded fashion. They will be followed for safety, immunogenicity and vaccine-specific anti-capsular pneumococcus (PNC) antibody persistence until 24 weeks post-delivery. Women who received placebo will be randomized to a second study step and will receive PCV-10 or PPV-23 at 24 weeks post-delivery. Antibody responses to the vaccine administered 6 months postpartum will be measured. Women who received placebo but cannot be randomized to a second study step due to ongoing new pregnancy will be enrolled in a third study step and receive open label PCV-10 at the last study visit; no data will be collected on these women and they will not be followed after vaccine administration. All infants will receive PCV-10 vaccinations per local standard of care.