[The action of the vaccinia virus upon placenta and fetus in revaccinated pregnants (author's transl)].

We studied 608 antivariolic revaccinated pregnants in spring 1972 at different ages of gestation. 60 presented spontaneous abortus; in 502 cases there has been performed therapeutical abortion, and 46 pregnants revaccinated after 2 1/2-3 months of gestation continued their pregnancy. Pregnancy and birth in revaccinated pregnants which did not abort, evolved without any difference against the witness-sample; the newborns presented in a higher percentage underweight. The absence of the vaccinia-virus and of Guarnieri-inclusions in the examined placentae and embryos as well as the moment of abortion, only after 20 days from the revaccination data, leads to the supposition that the placental lesions do not seem to be produced by the direct action of the virus by its replication, but probably by reactions of hypersensibility of the late type against the alergizin antigens of the antismallpox vaccine. The antivariolic revaccination of the sample of pregnants, showed that the vaccinia virus did not present a malformative action upon the embryo, but in change the abortive action was manifest in indirect proportion to the age of gestation.