SILVA-ROSALES, Norma Angélica; TENE, Carlos Enrique; CERVANTES-KARDASCH, Víctor Hugo    TORO, Mario Del. Comparison of the immune response against strains of S. pneumoniae, assessed by hemagglutination, in children immunized with heptavalent conjugated pneumococcal vaccine (two primary vaccinations with or without reinforcement). Bol. Med. Hosp. Infant. Mex. []. 2012, 69, 2, pp.97-103. ISSN 1665-1146.

Background. Different patterns of heptavalent conjugated pneumococcal vaccine immunization have proven effective. Although three and four doses are recommended, there are still children who are administered schemes of two primary vaccination doses without reinforcement. The aim of this study was to compare the immune response against S. pneumoniae in children (group A and group B) submitted to different immunization schemes (two primary vaccination doses with or without reinforcement). Methods. We conducted an observational, cross-sectional study comparing the immune response between group A and group B, analyzing the weak immune response with positive hemagglutination dilution ≤1:2. Odds ratio (OR) and Fisher's exact test were used. Results. There were no clinical differences between group A (n = 14) and group B (n = 15). There was a higher proportion of weak immune response in group A (57% vs. 13%, OR 8.7 (95% CI 1.3-53.8, p = 0.017). Conclusions. Weak immune response against S. pneumoniae is higher in schemes primed with two doses of heptavalent conjugated pneumococcal vaccine without reinforcement than using the two-dose schedule + a booster of heptavalent conjugated pneumococcal vaccine.

: S. pneumonia; heptavalent conjugated pneumococcal vaccine; vaccination; hemagglutination; immune response; immunization.