Hepatitis B vaccine in developing countries: problems and prospects.
Hepatitis B vaccines are highly immunogenic. To determine the efficacy of low doses and of the intradermal route of vaccination, 197 Nigerian children were given 3 monthly doses of Hevac B. Of these, 96 had 2 micrograms subcutaneously and 101 had 2 micrograms intradermally. One month after completing the schedule, 82.3% and 74.3% of the respective groups had become anti-HBs positive without adverse side-effects. In the second part of the study, 50 chronic HBsAg carriers were vaccinated. Compared to placebo-treated carriers, no effect was demonstrated with regard to HBsAg clearance or anti-HBs production. Immune complexes were not attributable to Hevac B. No untoward effects were noted. Booster vaccination of 50 initial non-responders resulted in the development of significant levels of anti-HBs in 20 (40%) of the recipients. None of the 'non-responders' developed clinical or virological evidence of HBV infection. It is concluded that low-dose vaccination is effective and that the intradermal route may be useful in developing countries.
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003906:Developing Countries; D006509:Hepatitis B / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000032:analysis*; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D017325:Hepatitis B Vaccines; D006801:Humans; D008875:Middle Aged; D009549:Nigeria; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage*
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D014761:Viral Hepatitis Vaccines