Immunological reactions of the Coxsackie viruses. III. Cross-protection tests in infant mice born of vaccinated mothers; transfer of immunity through the milk.

Maternal antibodies to the Coxsackie viruses (C virus) are conveyed to newborn mice through the colostrum and milk. of vaccinated mothers. No evidence for or against placental transmission of immunity was obtained. The immunity conferred on the young is type-specific. Immunity may be conferred to infants born of non-immune mice by allowing a suckling period of 24 to 48 hours with an immune mother. Immunity appears to be transferred through the milk for the duration of lactation. Strains of C virus can be typed by challenging infant mice born to mothers vaccinated with known types according to the outline presented above. Complement-fixing antibodies are also transferred from vaccinated mother mice to their offspring.