WEDNESDAY, May 19 (HealthDay News) -- Babies aren't scheduled to be vaccinated against measles until they turn a year old, but new research suggests that infants are vulnerable to the disease from the time they are 2 to 3 months old until they get their shot because the immunity they inherit from their mother wears off.

The study, based on an examination of the medical records of 207 healthy women and babies at five Belgian hospitals in 2006, was published online May 18 in BMJ.

Among the mothers in the study, the women who had contracted the measles at some point in their life became immune and gave more of an immune boost to their babies than women who were vaccinated and never experienced the illness.

Still, protection derived from the mother only lasted from one to four months for all the women. Between 95 percent and 99 percent of the infants had lost the components of their immune systems, known as antibodies, that target measles by the time they were 6 months old.

"This finding is important in view of recent outbreaks and is an argument for timeliness of the first dose of a measles vaccine and vaccination of traveling or migrating children under the age of 1 year," study author Elke Leuridan, of the Center for the Evaluation of Vaccination at the Vaccine and Infectious Disease Institute at the University of Antwerp, and her colleagues wrote.

More information

The Nemours Foundation has more on measles.