Serogroup B
Neisseria meningitidis (MenB) is a major cause of invasive
disease in early childhood worldwide. The only MenB
vaccine available in
Brazil was produced in
Cuba and has shown unsatisfactory
efficacy when used to immunize millions of
children in
Brazil. In the present study, we compared the specific functional
antibody responses evoked by the Cuban MenB
vaccine with a standard
vaccine against
diphtheria (DTP
diphtheria,
tetanus,
pertussis) after primary
immunization and boosting of
mice. The peak of bactericidal and opsonic antibody titers to MenB and of
neutralizing antibodies to
diphtheria toxoid (DT) was reached after triple
immunization with the MenB
vaccine or
DTP vaccine, respectively. However, 4 months after
immunization, protective DT antibody levels were present in all DTP-vaccinated
mice but in only 20% of the
mice immunized against MenB. After 6 months of primary
immunization, about 70% of
animals still had protective neutralizing DT
antibodies, but none had significant bactericidal
antibodies to MenB. The booster doses of DTP or MenB
vaccines produced a significant antibody recall response, suggesting that both
vaccines were able to generate and maintain
memory B cells during the period studied (6 months post-triple
immunization). Therefore, due to the short duration of serological
memory induced by the MenB
vaccine (VA-MENGOC-BC®
vaccine), its use should be restricted to
outbreaks of
meningococcal disease.