DURATION OF ANTIBODY-RESPONSE AFTER MENINGOCOCCAL POLYSACCHARIDE VACCINATION IN US AIR-FORCE PERSONNEL

The long-term kinetics of the immunologic response after vaccination o f adults with Neisseria meningitidis polysaccharide vaccine is unknown . Total meningococcal anti-capsular antibody response (measured by ELI SA) and serum bactericidal activity after routine vaccination with qua drivalent meningococcal vaccine were evaluated in US Air Force personn el. In a retrospective cross-sectional study, blood samples were obtai ned from similar to 40 personnel before vaccination, at 1 and 4-6 mont hs, and at 2, 3, 4, 6, 8, and 10 years after vaccination. Total anti-g roup A and -group C capsular antibody levels-and bactericidal activity peaked 1 month after vaccination and declined substantially by 2 year s. At each interval, significantly higher levels of total antibody and bactericidal activity were detected than before vaccination. Anti-cap sular antibodies and bactericidal activity persisted for up to 10 year s after immunization. These and further studies on the serologic measu re of protection against meningococcal disease are important for evalu ation of candidate vaccines and development of recommendations for imm unization.