Review on the immunogenicity and safety of PCV-13 in infants and toddlers.

Pneumococcal polysaccharide-protein conjugate vaccines (PCVs) generally protect against vaccine-serotype-specific pneumococcal disease. Additional serotypes included in the new 13-valent PCV (PCV-13) formulation and not in the first-generation 7-valent PCV (PCV-7) formulations are 1, 3, 5, 6A, 7F and 19A. Importantly, serotype 1 is associated with a high proportion and burden of pneumococcal disease in low-income countries, whilst serotype 19A emerged as the dominant disease-causing serotype following widespread PCV-7 immunization in the USA. In this article we present the available data on the immunogenicity and safety of PCV-13 in infants and children. Noninferiority studies indicate a similar immunogenicity profile between PCV-13 and PCV-7 recipients against most of the common serotypes. A favorable immunogenicity profile was also observed for at least five of the additional serotypes in PCV-13. An attenuated anamnestic response to serotype 3 was reported in five out of 14 studies. PCV-13 was demonstrated to have a similar acceptable safety profile to PCV-7 and no interference in immunogenicity of other concomitantly administered childhood vaccines was observed among PCV-13 recipients.