Background: The 13-valent pneumococcal conjugate vaccine (PCV13) has been demonstrated to be immunogenic and safe for administration to infants and children aged <5 years. PCV13 recently was approved for children and adolescents aged up to 17 years as the vaccine may be of benefit to some in this older age group.
Methods: In this open-label study, healthy children aged ≥5 to <10 years (ie, the younger age group) previously vaccinated (≥1 dose) with 7-valent PCV (PCV7) and pneumococcal vaccine-naïve children aged ≥10 to <18 years (ie, the older age group) received 1 dose of PCV13. For the younger group, antipneumococcal immunoglobulin (Ig) G geometric mean concentrations 1 month postvaccination were compared with posttoddler dose (PCV13 or PCV7) levels from a historical control study. Opsonophagocytic activity geometric mean titers 1 month postvaccination for the older group were compared with the younger age group. Safety data were collected.
Results: Five hundred and ninety-eight children were enrolled, 299 in each age group. For PCV7 serotypes, IgG geometric mean concentrations in the younger group were 8.23-53.56 μg/mL, ≥2.5-fold greater than historical posttoddler dose values. For the 6 additional serotypes, IgG geometric mean concentrations in the younger group were 2.38-21.51 μg/mL, ≥1.2-fold greater than historical posttoddler dose values. Opsonophagocytic activity geometric mean titers were similar in the older and younger age groups, except for serotype 3 which was lower in the older group. Safety was comparable in both groups.
Conclusions: PCV13 was immunogenic and safe when administered to older children and adolescents, regardless of prior PCV7 vaccination.
Trial registration: ClinicalTrials.gov NCT00761631.