Although dramatic progress has been made in the United States in controlling measles, incidence rates elsewhere in the world remain high. In developing countries nearly 1 million children die of measles each year, with the highest rates of disease and death occurring among infants in the first year of life. Successful control of measles in this age group is impeded principally by the short interval available for successful vaccination early in life—from the time maternally derived antibodies wane to the time exposure to natural measles occurs.
The recent clinical trials of live, aerosolized measles virus vaccines1-3 have demonstrated that this alternate route of administration may prove to be particularly useful in developing countries because seroconversion can be induced in the presence of maternal antibodies. Infants were immunized successfully at an earlier age—as early as 4 months—than is possible by the parenteral route, allowing a longer interval for vaccination before exposure
Amler RW, Orenstein WA, Bart KJ. The Immune Response to Aerosolized Measles Vaccine. JAMA. 1984;251(18):2408. doi:10.1001/jama.1984.03340420074030