The study is the first to document this increased susceptibility and provides further evidence for measles vaccination at 12-15 months. Papania is acting chief of the Measles Elimination Activity branch of the CDC's National Immunization Program. The study involved about 125 unvaccinated infants younger than 15 months who were exposed to measles in the early 1990s. Mothers were interviewed by telephone for details of measles exposure and outcome, demographic data, and medical and vaccination history. Papania explains that infants rely on maternal antibodies for protection against measles.
Antibodies are molecules in the immune system that help the body fight infection.
During pregnancy, antibodies are transported from the mother to the developing fetus. Antibodies against measles form following a measles infection or after receiving a measles vaccine. When a woman is immune to measles due to having a vaccine, lower antibody levels develop than if she developed immunity to the disease after having had measles herself, according to Papania. That is exactly what we found. Currently, the CDC recommends that children be vaccinated against measles at 12-15 months of age.