Seroconversion after three doses of intramuscular rabies vaccine as a post-exposure treatment

Abstract

Rabies is still threatening half of the world’s population with the global burden of canine rabies being estimated as 59,000 human deaths, annually. With no cure existing for clinical rabies, post-exposure prophylaxis (PEP) is the only certain means to save lives of the exposed people. In Iran, bite incidences exceed 180,000 per year, where all victims receive 5 vaccine doses for PEP, conforming to the Essen regimen. More than two-thirds of the exposed individuals stop receiving treatments after day 7, for the reason of being exposed to a non-rabid dog or cat. According to the national standard protocols, these individuals should re-start a complete 5-dose PEP course upon the re-exposure. New WHO recommendations based on scientific data is encouraging revisions to the existing prophylaxis programs. In order to know if an incomplete Essen regimen can provide adequate immunity, in the present study, 5 groups of individuals who had only received 3 first doses of the Essen regimen within the previous 1, 3, 6, 12 and 24 months were examined for immunity against rabies. Our results indicated sufficient anti-rabies neutralizing antibody in all individuals, before and after receiving two standard booster doses (i.e. days 0 and 3). This might also suggest the adequacy of the 3 first doses of vaccination, as a one-week long post-exposure vaccination program.