Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine (PCV13) when given as a toddler dose to children immunized with PCV7 as infants

► PCV13 was given as a single toddler dose in children previously vaccinated with PCV7. ► Results were compared to children receiving a 4-dose series of PCV7 or PCV13. ► A toddler dose of PCV13 after 3 doses of PCV7 should provide expanded protection.