Immunization of mice against Coxsackievirus B3 and prevention of foetal growth retardation.

Coxsackievirus B3 infection in pregnant mice leads to a severe pancreatitis with a retardation of foetal growth and increased wastage. The present study demonstrates that animals may be immunized actively or passively against this infection to allow foetal development to proceed normally. Active immunization was achieved by injecting a low dose of live virus into 4-week-old animals. These mice were then mated at 10 weeks and given a high dose of virus on the eighth day of pregnancy. Examination at 18 days' gestation revealed that foetal growth was not significantly different from the controls injected with heat-killed virus, and pathological changes in the mothers were not seen. Animals were passively immunized against Coxsackievirus B3 in pregnancy by injecting serum from immunized animals 1 day before the high dose of live virus was given. This procedure also protected against the effects of the virus and litter sizes and foetal weights were normal.