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Pneumococcal conjugate vaccine (PCV) efficacy is lower for noninvasive pneumonia than invasive disease. In this study, participants were immunized with 13-valent PCV (PCV13) or hepatitis A vaccine (control). Bronchoalveolar lavage samples were taken between 2 and 6 months and serum at 4 and 7 weeks postvaccination. In the lung, anti-capsular immunoglobulin G (IgG) levels were higher in the PCV13 group compared to controls for all serotypes, except 3 and 6B. Systemically, IgG levels were elevated in the PCV13 group at 4 weeks for all serotypes, except serotype 3. IgG in bronchoalveolar lavage and serum positively correlated for nearly all serotypes. PCV13 shows poor immunogenicity to serotype 3, implying lack of protective efficacy. Clinical Trials Registration. ISRCTN 45340436.

Original publication




Journal article


J Infect Dis

Publication Date





1626 - 1631


BAL, PCV13, anti-capsular IgG, pneumococcus, Antibodies, Bacterial, Humans, Immunoglobulin G, Infant, Lung, Pneumococcal Infections, Pneumococcal Vaccines, Serogroup, Vaccines, Conjugate