Haemophilus influenzae type b infections and its prevention by vaccines

Haemophilus influenzae type b (Hib) infections and its prevention by vaccines are reviewed. Its prevalence is underestimated, due to technical pitfalls in the laboratory and to the difficulties of diagnosing respiratory infections, chiefly pneumonia. Taking into account all infections (respiratory, meningitis and others), Hib is probably the most important pathogen, compared to S. pneumoniae and N. meningitidis. The incidence of Hib meningitis in Brazil is presented and risk factors are discussed, as well as the preventive alternatives. The different Hib vaccines are analyzed and schedules of immunization with two of them (PRP-T and HbOC) are presented. Possible eradication of Hib diseases is discussed.