Rabies serum neutralizing antibody in mongooses from Grenada.

During a four-year study on Grenada, 4,754 mongooses were examined, of which 100 (2.1%) were rabid. Of 1,675 mongooses tested for rabies serum neutralizing (SN) antibody, 498 (30%) were positive. During these four years (1971-74) the antibody prevalence rate increased from 20.8% to 43.2%, whereas the number of rabid mongooses decreased from 3.5% to 0.6%. Naturally acquired antibody was monitored in 20 captive mongooses for up to 35 months, and it was still circulating in 18 when monitoring ceased. The highest titre recorded was 1:1,400, and the rate of fall was greatest in mongooses with high initial titres. High titres of naturally acquired antibody suggest recent rabies activity. 14 mongooses vaccinated parenterally with 1.0 ml of attenuated ERA vaccine showed substantial increases in antibody titres; most had titres greater than 1:1,000 one month later and maintained a high titre for several months. The highest recorded was 1:34,800. The virus titres of brain material from rabid mongooses ranged from 10(1.8) to 10(4.3) and, in some cases, were only slightly lower than those of salivary gland tissue (range, 10(1) to 10(5.6).

A comparison of a WI-38 vaccine and duck embryo vaccine for preexposure rabies prophylaxis.

Two types of rabies vaccine, WI-38 vaccine (WRV) and Duck Embryo Vaccine (DEV) were compared in rabies preexposure prophylaxis. Once group of veterinary students received four doses of DEV, a second group received four doses of WRV, and a third group received two doses of WRV. Adverse reactions were found to be similar for all three gorups. The antibody responses, however, differed markedly: the mean neutralizing titer after four doses of DEV was 1:75, after four doses of WRV was 1:1517, but was only 1:164 after two doses of WRV. All students who received three or four doses of WRV developed high titers of rabies antibody, making this vaccine very desirable for preexposure prophylaxis.

Human rabies globulin and human diploid vaccine dose determinations.

Veterinary students were injected with either human rabies immune globulin and human diploid rabies vaccine, or with human diploid vaccine alone. All those students who received three or more doses of the vaccine developed high levels of neutralizing antibodies by the rapid fluorescent focus inhibition test (RFFIT). The levels of early antibody in the students receiving the combination of globulin and vaccine depended very much on the dose of globulin. The neutralizing antibody levels in the sera of students who received 12 IU/kg were low 48 hours after the globulin injection: 6 of the 25 students receiving this dose were found to have no antibody, and eight were found to have titers between 1:6 and 1:10. When the globulin dose of 20 or 30 IU/kg was administered all students had early titers of 1:11 or above and all students subsequently developed high levels of antibody.