Risk of measles present in first year

June 1, 2010

A mother's antibodies that can help shield her infant from getting measles may not last long, according to new research.

A mother's antibodies that can help shield her in- fant from getting measles may not last very long, increasing her baby's risk for measles well before the 12-month vaccination, new research published online May 18 in BMJ shows.

Antibodies extended immunity for a median of 0.97 months in infants of vaccinated women, according to researchers at the University of Antwerp, Belgium. Babies born to women with naturally acquired immunity had more protection-a median of 3.78 months-until necessary levels of the maternal measles antibodies disappeared.

By age 6 months, researchers noted that more than 99% and 95% of infants, respectively, did not have any more maternal antibodies against measles.

At the 1-, 6-, 9-, and 12-month follow-up visits, infants of vaccinated women had lower antibody concentrations. Immunity remained steady in 29% of infants born to vaccinated women and 60% of infants born to women with naturally acquired immunity by 3 months of age. No infant in the study had adequate maternal antibodies at age 9 or 12 months.