Objective: To evaluate the safety and immunogenicity of the booster dose of 7 valent pneumococcal conjugate vaccine (PCV7) to the healthy Chinese toddlers who had received 3 primary doses.
Methods: Four hundred and eighty-eight Chinese toddlers received a booster dose of PCV7 at age of 12-15 months following a primary series of the vaccine given at ages 3, 4, 5 months separately with Diphtheria Tetanus Acellular Pertussis Combined Vaccine (DTaP) in Group 1 or concurrently with DTaP in Group 2. Following the booster dose immunization, each subject was followed up for 30 days to observe the safety of the vaccine. Blood samples were taken from a subset of subjects prior and post 30 days the booster dose immunization to evaluate immunogenicity.
Results: A high proportion of subjects in Group 1 (89%) and Group 2 (91%) remained afebrile after the booster dose. Local reactions to the PCV7 booster dose were generally mild. For each serotype, the rise in GMC (post-/pre-vaccination) showed a statistically significant difference (P<0.0001) between both groups.
Conclusion: PCV7 administered as a booster dose is generally safe, well tolerate, and immunogenic in healthy Chinese toddlers.