Unresponsiveness to conjugate Pneumococcal polysaccharides in children with recurrent respiratory infections

To establish the antibody response rate in children with recurrent infections and fully immunized with the Pneumococcal 7-valent Conjugate vaccine. We have analyzed 39 patients referred to our clinic with recurrent infections despite complete immunization with the Pneumococcal 7-valent Conjugate vaccine for age, according to ACIP guidelines. We assessed the patients by checking their immunization status and the antibody titers to all 7 Streptococcus pneumoniae serotypes included in the vaccine (4, 6B, 9V, 14, 18C, 19F, 23F) assessed by standardized ELISA. The patients were assembled into 3 groups, a non-immunized group with laboratory data prior to the vaccine, and an immunized group consisting of responders and non-responders according to their antibody titer (>1.3 or