Immunogenicity and safety of DTPw-hepatitis B combined vaccines.

INDIAN PEDIATRICS 815 VOLUME 45__OCTOBER 17, 2008 Hepatitis B virus infection is one of the major global health problems despite the availability of prophylactic vaccines. The WHO-Expanded Program on Immunization (WHO-EPI) recommends immunization of all infants against hepatitis B. The best way to achieve this goal of universal vaccination is by employing vaccine formulations combining the hepatitis B vaccine with the diphtheria, tetanus and whole-cell pertussis (DTPw) vaccine. The immunization schedule and adjuvant (aluminium salt) used in individual vaccine formulations are compatible. Studies have shown that hepatitis B component in the combined vaccine does not impair the immune responses to the other three components of the tetravalent vaccine, and the safety profile of the combined vaccine has been reported to be similar to that of the classical DTPw vaccine(1). Integration of the combined vaccine into the routine immunization program should be a positive step towards protecting infants against hepatitis B virus. In this issue of the journal, Shah and colleagues(2) have compared the immunogenicity and safety of an indigenous DTPw-Hepatitis B combined vaccine (ShantetraTM) with the Tritanrix HBTM vaccine in healthy Indian infants. They conclude that the present study has effectively demonstrated the safety and immunogenicity of Shantetra vaccine. Many clinical studies have shown the excellent immunogenicity of each component(1,3,4). However, the GMT antibody titers reported by Shah, et al.(2) are well below the previously published limits (see Table I for comparison), raising some concern. While upper confidence intervals compare well with the reported values, lower confidence interval for HBs