Is Estimation of The Rubella Serum Antibody Level of The Women Before Marriage Justified?

52 pregnant women, not vaccinated at all in their lives against rubella, came intentionally in contact with a patient suffering from Rubella infection. After this exposure their immune status have been determined. The fear of these pregnant women to bear a disabled child was behind this seroepid study.
67% of them were already immune as a result of previous infection.
17% of them were despite this exposure still not infected, they are now susceptible to the Rubella infection. Only 15% of them contract the Rubella infection, most of their infants are really at risk to be born disabled, because they were in the first trimester.
That fear can be abolished, by routine vaccination against Rubella, prior to marriage especially in the developing countries, where adult females are rarely vaccinated against Rubella.