Congenital rubella syndrome is a constellation of
birth defects that can have devastating consequences, impacting approximately 100,000 births worldwide each year. The incidence is much lower in countries that routinely vaccinate their population. In the US, postnatal immunization of susceptible women is an important epidemiological strategy for the prevention of
rubella as the Center for Disease Control (CDC) does not recommend administering this
vaccine during pregnancy due to its nature as a live attenuated virus
vaccine. However, concerns that the co-administration of
rubella vaccine with other immunoglobins (i.e.,
Rhogam) could compromise
vaccine efficacy has produced warnings that can delay the administration of
rubella vaccination postpartum, leaving women susceptible to the disease in subsequent pregnancies. We aimed to address whether the co-administration of the
measles,
mumps, and
rubella (
MMR) vaccine and
Rhogam decreased antibody responses compared to those receiving only MMR vaccination. This retrospective cohort study utilized clinical data from 78 subjects who received the
MMR vaccine and
Rhogam after delivery and 45 subjects who received the
MMR vaccine alone. Maternal demographics,
pregnancy complications and
rubella status at the start of a subsequent pregnancy were recorded for analysis. Overall, the two cohorts had similar baseline characteristics; however, lower parity was noted in the participants that received both MMR vaccination and
Rhogam. Making assessments based on maternal
antibody IgG index for
rubella during the next pregnancy, we observed that 88% of the
Rhogam +
MMR vaccine group had positive serology scores, which was not significantly different from the 80% rate in the
MMR-vaccine-only cohort (p = 0.2). In conclusion, no differences were observed in
rubella immunity status in subsequent pregnancies in those mothers given both the
MMR vaccine and
Rhogam concurrently. Given these findings, warnings against co-administration of
vaccines in combination with
Rhogam appear unwarranted.