Rabies antibody titers in vaccinees: protection, failure and prospects

Treatment of symptomatic rabies is a challenging task as no effective drug is yet available. Hence, prophylactic immunization is an important step. The development of adequate level of antibody (greater than or equal to 0.5 IU/ml serum) is necessary for protection against the disease. In contrast to the nerve tissue vaccines, tissue culture vaccines particularly human diploid-cell strain type is highly potent and least reactogenic. To minimize the costs of immunization by this expensive vaccine, small dose intradermal administration has been advocated for developing countries with endemic rabies. Concurrent use of serum and antimalarials may interfere with adequate immune response. Efforts are in progress for the development of more potent subunit and recombinant antirabies vaccine for future human use. This review makes an attempt to study the antibody levels in the vaccinees regarding its role in the protection and failure against clinical and experimental rabies.