Accelerated neutralizing antibody response to rabies vaccination six month after a single intramuscular pre-exposure dose

Abstract

Background and objective: Rabies is still a serious public health problem in much of Asia. Management of severe exposures includes use of immunoglobulin which is expensive and scarce in regions where needed the most. Pre-exposure vaccination of subjects at risk eliminates need for immunoglobulin in case of an exposure. Pre-exposure vaccination schedules require 3 injections of tissue culture vaccine over 2-4 weeks. It would be desirable to learn if a reduced dose might be able to induce an adequate immune response. Method: Thirteen volunteers received one intramuscular dose of a WHO recognized commercial rabies vaccine. All had detectable neutralizing antibodies six months later and developed an accelerated immune response when given a simulated post-exposure rabies vaccine series. Results: This study suggests that one intramuscular injection of purified vero cell rabies vaccine provides immune memory for at least 6 months. This study needs to be repeated with a larger number of subjects for a longer period of time as it may be of interest for selected populations.