PCEC Rabies Vaccine and HRIG in Post-Exposure Protection against Rabies

Abstract

The encouraging results of purified chicken embryo cell culture (PCEC) rabies vaccine clinical trials in healthy volunteers have provided us with sufficient scientific and ethical ground to attempt a study applying this new vaccine in post-exposure protection against rabies. Consequently, a protocol was designed in accordance with the requirements and recommendations of the WHO Expert Committee for Rabies for the treatment of persons exposed to rabies virus through bite/contact with a proven rabid animal. According to this protocol it was required that the treatment commence within 24 h after the bite/contact. To all such persons 1 ml of PCEC vaccine was given i.m. in the deltoid muscle on days 0, 3, 7, 14, 30 and 90. Simultaneously with the vaccine, human rabies immune globulin (HRIG) was applied on day 0 in the amount of 20 IU/kg of body weight. The study was carried out in March 1983 and included 10 cases (only those cases are taken into account where the animal was later proven as rabid). Three of them had been handling and skinning a marten, five were exposed while skinning a rabid fox, one was bitten by a rabid cat and one by a rabid badger. Reactogenicity of PCEC and HRIG was mild, i.e. within the limits of PCEC given alone. Blood samples for rabies antibody determination were taken on days 0, 7, 14, 30, 90 and 100 (sera are currently being tested at the Behring Institut, Marburg and the Institute of Immunology Zagreb). Several months have now passed from the exposure and treatment of these persons and they are all in good health. This limited experience in post-exposure protection against rabies with PCEC vaccine and HRIG supports the expectation that the new generation of low-cost, high-potency tissue culture rabies vaccines will contribute to the prevention of human rabies, particularly in developing countries where rabies is a permanent danger.