Persistent fetal rubella vaccine virus infection following inadvertent vaccination during early pregnancy

Inadvertent immunisation of seronegative women with RA27/3 rubella virus live-attenuated vaccine several weeks before and after conception is described. Whereas in 5 cases the vaccine virus was not transmitted vertically, in 1 case vaccination led to the development of persistent fetal infection with prolonged virus shedding for more than 8 months. Sequence analysis carried out on isolates from amniotic fluid, from cord blood leukocytes as well as from infantile urine confirmed an infection by the vaccine strain. At birth, the newborn infant exhibited none of the symptoms compatible with the congenital rubella syndrome and signs indicative for development of late onset disease are not apparent. This observation constitutes the first unequivocal documented case of rubella vaccine virus related to persistent fetal infection.