The Effect of Separate Inoculation of Serum and Virus Upon the Protection-Test in Vaccinia

Abstract

That the serum of an animal actively immunized to a virus may afford some protection against infection when a mixture of that serum and active virus is injected into a susceptible animal is commonly accepted. It is also generally agreed that immune serum, injected at a suitable period of time before inoculation of the infectious agent, may afford passive protection. On the other hand, the ability of immune serum to protect, when it is administered subsequent to the inoculation of the infectious agent, has not been uniformly conceded. Andrews (1) showed that vaccinal immune serum injected into a rabbit's skin 24 hours before the intracutaneous inoculation of vaccine virus prevented the appearance of a lesion, provided that the dose of virus was not too large. In a later paper (2), he also showed that immune serum injected as long as 4 hours after the injection of virus modified the course of the disease in that the lesions were smaller than those appearing at sites injected with virus only.