Serum antibody level in rabbits submitted to antitetanus active-passive immunization with heterologous horse serum.

Serum antibody titres have been assessed in rabbits submitted to active and active-passive immunization against tetanus with AlPO4 adsorbed vaccine and horse heterologous immune serum. Heterologous antibodies survive in the blood stream no more than six days. Endogenous antibodies, with the adopted vaccination schedule, emerge fifteen days after the first vaccine inoculation. In rabbits undergoing active-passive immunization, the appearance time of endogenous antibodies is delayed, all the more so as the antiserum injected dose increases. Such data stress the opportunity to give up with the use of heterologous immune sera in tetanus prophylaxis, in association with vaccine as well.