The antimeningococcal vaccine VAMENGOC B-C induced poor serum and salivary antibody response in young Brazilian children.

In 1989 about 2.3 million Brazilian children received the antimeningococcal vaccine VAMENGOC B-C (Havana, Cuba). We evaluated the serum and secretory immune response of vaccinated children by enzyme-linked immunosorbent assay with outer membrane complex antigens. Western blotting and bacterial adherence inhibition assays with human buccal epithelial cells were performed with some of the samples. Serum and salivary antibody concentrations to Neisseria meningitidis Group B of vaccinated children < 4 years old were not significantly higher than those of nonvaccinated children, as observed in convalescing patients used as positive controls. Older children (4 to 6 years old) presented a slight increase in antibody OD indexes. Sera and saliva from vaccinated children showed a weak reaction with meningococcal antigen by Western blotting and were unable to inhibit significantly the adherence of N. meningitidis B to buccal epithelial cells. These data suggest that this vaccine induced a poor serum and salivary antibody response in the population studied.