Immunisation with Inactive Vaccinia Virus

Abstract

Experiments were carried out on rabbits, guinea-pigs and monkeys to test the immunity produced by vaccinia virus killed with heat, phenol or formalin. Before use, the vaccines were rigorously tested for their inactivity by a method of inoculation and triple passage in series. The test of immunity was quantitative. The rabbit experiments gave equivocal results but indicated that a slight immunity was produced in some cases. In guinea-pigs more success was obtained: they could be protected against one to ten minimal infecting doses and showed a partial immunity to stronger tests. Monkeys were only tried in one experiment in which a weak vaccine was used. This did not protect them. The superiority of guinea-pigs for this kind of work is discussed as also the bearing of the results obtained with them on the nature of immunity to vaccinia virus.