Rubella Vaccination of Unknowingly Pregnant Women During 2006 Mass Campaign in Argentina

We report a prospective study of 56 pregnant women inadvertently vaccinated with rubella vaccine during the 2006 campaign performed in Argentina. Of these patients, 48 (87%) were immune, whereas the remaining 9 (16%) were susceptible. In the latter group, 7 presented with a primary reaction to the vaccine confirmed through immunoglobulin (Ig) G antibody avidity testing or seroconversion of IgG titers. During the clinical and laboratory follow-up, newborns did not present evidence of infection or malformations compatible with congenital rubella syndrome. Rubella is a highly contagious acute exanthematous disease that affects both children and adults, with minor morbidity and few complications. The highest risk occurs when susceptible pregnant women are exposed to the virus during the first months of pregnancy, when infection with the virus can cause congenital rubella syndrome (CRS) and may have disastrous effects on the fetus. Since the vaccination against rubella was introduced in the United States, the incidence of the disease has decreased by 99%. Similar results have occurred in many countries of the Americas that have obligatory vaccination schemes, such as Argentina. The measles-mumps-rubella vaccine with viral type RA27/3 attenuated virus was introduced in Argentina in 1998; subsequently, a major decrease was noted in the number of reported cases of