[The serological response to a recombinant DNA vaccine in the native residents of 2 hyperendemic hepatitis B areas in the Peruvian Amazonia]

Abstract

In large areas of the Amazon jungle from Brazil, Colombia, Venezuela and Peru, it has been reported hyperendemic HBV and delta focus. In the Peruvian jungle we found up to 97% of prevalence of HBV, on the northern Jívaro tribes vs the southern tribes, Arawak, (65%). In this paper we studied 226 volunteers from 6 Jívaro and 3 Arawak villages, who accepted to be vaccinated with a DNA recombinant vaccine (ENGERIX B); all of them were previously HBsAg/Ab negatives but 55.5% of them were anti-core (IgG) positive. Our results show 84.9% of seroconversion to anti-HBs, and 73.5% was consider to be immunized (> 10 mIU/ml). Better response was observed in those that were HBcAb negative, coming from a low endemic area. We also observed a good vaccine response although we had to change months the response decreased up to 51.8% of seroimmunity. Higher anti-HBs titles was observed in the southern tribes: MGC of 416.3 mIU/ml. compared with the south: MGC: 182.2 mIU/ml.

Conclusions: It is important to check previously, in hyperendemic areas, HBV markers, specially. It is important to receive the second dose between with the third dose up to 14 month. The immune response overall was good: the ABsAb titles obtained was in average, 290 mIU/ml (10.2-41,00). Apparently the vaccine do not suffer during the difficulties in transportation in the jungle. No side effects we shown during the vaccination program.