Response of laboratory staff to vaccination with an inactivated Rift Valley fever vaccine--TSI-GSD 200.

Laboratory staff and students were vaccinated with a formalin-inactivated rift valley fever (RVF) vaccine. This study showed that the vaccine used (TSI-GSD 200) was able to bring about the production of antibodies in recipients. For the production of a high titered antibody response, three doses of the vaccine were required. One or two doses of the vaccine did not produce a greater than four-fold rise in antibody titre. A greater than four-fold rise in antibody titre following vaccination, is considered significant. The complete dose of the vaccine, that is, three doses, was necessary for protection. This study also showed that the haemagglutination inhibition (HI) test was capable of detecting antibodies, few weeks post vaccination. Though such HI antibodies broaden with time, it could be used for screening purposes and a more specific test, e.g., plaque reduction neutralisation (PRN) test used for confirmation of such results.