Studies on the Assay of Smallpox Vaccine

Report 3. Assay with a rabbit preliminarily immunized by passive immunization

Abstract

“Twofold” difference of vaccinia virus content in smallpox vaccine can be detected on a rabbit immunized with vaccinia immune serum by intradermally inoculating 0.05m1 of the serial twofold dilutions of smallpox vaccine 24 hours affter the injection of immune serum.
The assessment of the end reaction on an immunized rabbit is apparently easier as compared with that on a normal rabbit.
With normal rabbit, it is hardly possible to find out 4-times difference in vaccinia virus content, because the reading of end reaction is not simple.