Thirteen-Valent Pneumococcal Conjugate Vaccine-Induced Immunoglobulin G (IgG) Responses in Serum Associated With Serotype-Specific IgG in the Lung

This study found that immunization with 13-valent pneumococcal conjugate vaccine elicits serotype-specific immunoglobulin G (IgG) responses, with serum IgG levels to correlate with those measured in bronchoalveolar lavage samples, but shows poor immunogenicity against serotype 3 in both sites. 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.

Automated summary

This study found that immunization with 13-valent pneumococcal conjugate vaccine elicits serotype-specific immunoglobulin G (IgG) responses, with serum IgG levels to correlate with those measured in bronchoalveolar lavage samples, but shows poor immunogenicity against serotype 3 in both sites.