Subclinical rubella reinfection in vaccinated women with rubella-specific IgM response during pregnancy and transmission of virus to the fetus.

This report concerns 2 cases of documented rubella reinfection during pregnancy in previously vaccinated women. The antibody response at reinfection comprised not only anti-rubella IgG but also IgM. In the first case the reinfection occurred between the 13th and 19th week of pregnancy and was followed by transmission of virus to the fetus (anti-rubella IgM in cord blood and persisting antibody activity). The child had no clinical signs of congenital rubella and is normally developed without hearing impairment at 41/2 years of age. In the second case the reinfection resulted from exposure in the 15th week of pregnancy; there were neither serological nor clinical signs of congenital rubella in the child. The reported case of fetal infection in spite of previous rubella vaccination of the mother does not discourage the use of rubella vaccine. Rubella vaccine induces long lasting immunity and protection from viremia in the vast majority of individuals.