Transference of Maternal Passive Immunity to Vaccinia Virus in Mice

Abstract

ADULT mice are highly resistant to experimental vaccinial infection, but suckling mice succumb to relatively low doses of virus introduced into the inter-scapular fat pad¹. Transfer of protective antibody from immunized dams to their offspring has been described in this species for the viruses of variola², herpes³, foot and mouth disease⁴ and Friend leukaemia⁵. In this communication, I report the transfer of antivaccinial immunity from actively immunized pregnant mice to their young. The Porton strain of albino mice and the WR strain of vaccinia virus were used throughout. The biological characteristics and method of assay of WR vaccinia virus are recorded by Turner⁶. A single batch of virus (titre 2 × 10⁷ plaque forming units (P.F.U.)/ml.) was used, collected from chick embryo fibroblasts and stored in small volumes at −70° C.