Haemophilus influenzae type b Vaccine

Lee, Hoan Jong

Abstract

Haemophilus influenzae type b (Hib) has been one of the most common causes of invasive bacterial infections in the young children during the pre-vaccine era. The polysaccharide vaccine developed in the 1970s was composed of the capsular polysaccharide of Hib. The polysaccharide vaccine was not not effective in children younger than 2 years old those who are the highest risk group. In the 1980s, the protein conjugate vaccine was developed employing diphtheria toxoid, tetanus taxoid or outer membrane protein of Neisseria meningitidis as carrier proteins. The protein conjugate protein is highly effective in young infants. In countries where Hib conjugate vaccine is included in routine immunization, Hib disease is almost eradicated. The incidence and spectrum of Hib disease vary among different countries. The incidence of Hib diseases among Korean infants and young children is lower compared to those of western countries; the incidence of Hib meningitis in children under 5 years of age is around 10 per 100,000 per year, compared to around 50 in the United States and 20-30 in the European countries. Immunogenicity of Hib vaccine in Korean infants is very good and the responsiveness of Korean infants to Hib vaccine vaccine is better than that of the U.S. infants, which may has implication for the apparently lower incidence of Hib disease in Korean children. Hib vaccine was introduced in the early 1990s, and has been recommended for high risk children and used as an optional vaccine among healthy infants. Hib vaccine is not included in the National Immunization Program yet, but the Committee on Infectious Disease, Korean Pediatric Society, have decided to include the Hib vaccine in the routine immunization program in 2008. Hib vaccine should be included in the National Immunization Program in the near future and a surveillance system for Hib disease should be established.