Immunoglobulins and immunogenicity of pneumococcal vaccination in preschool asthma.

Pneumococcal vaccination is advocated for asthmatics. Although routinely performed, data supplying evidence for this recommendation are limited. We examined the immunological background of 215 asthmatic children (2-5 year old) at a university children's hospital and compared the immunogenicity of the recommended pneumococcal vaccines. Testing encompassed serum immunoglobulins, immunoglobulin G (IgG)-subclasses, and pneumococcal antibodies against serotypes 4, 6B, 9V, 14, 18C, 19F and 23F. An infection-prone subgroup received one dose of 23-valent pneumococcal polysaccharide vaccine (PPV-23; n = 38, median age 45 months) or of 7-valent conjugate vaccine (PCV-7; n = 23; median age 35 months). Pneumococcal antibodies were determined again after 4 weeks. Low immunoglobulin- and/or IgG-subclass levels were found in 27 subjects (14 infection-prone). Prevaccination pneumococcal antibody levels ranged from 0.36 to 1.06 microg/ml, depending on the serotype. The percentage of subjects with putative protective antibody levels > or =1.0 microg/ml ranged only from 19.9% to 54.1%, over all. Postvaccination, antibody geometric mean concentrations increased significantly higher in PCV-7 vaccinees for serotype 14 (p < 0.01) and 23F (p < 0.05). Now the percentage of putatively protected subjects ranged from 40.9% (serotype 6B) to 90.9% (serotype 19F) following PCV-7 compared with 31.6% (serotype 6B and 23F) to 81.6% (serotype 19F) in PPV-23 vaccinees. Our data give further evidence for pneumococcal vaccination of asthmatic children. PCV-7 is at least as immunogenic as PPV-23. Moreover, for children suffering from persistent asthma, PCV immunisation should be considered.