Immunization against measles by aerosol.

About 20 years ago, Japanese and American investigators found that inhalation of relatively small amounts of aerosolized, partly attenuated measles vaccines was consistently immunogenic in nearly all susceptible children. The resulting modified measles was not transmissible to susceptible children. In 1965-1966, Japanese investigators showed that levels of neutralizing antibody produced by killed measles virus vaccine, which prevented subsequent immunization when live vaccine was given subcutaneously, did not prevent the immunogenic effect of the same vaccine given by aerosol. This raised the possibility that aerosolized vaccine may be immunogenic in infants with residual maternal antibody, in whom subcutaneously injected vaccine is ineffective. In 1971, Soviet investigators reported the high effectiveness and complete lack of febrile and other clinical reactions in 3,306 children who were exposed in large groups in large tents or chambers to aerosols of the more-attenuated measles vaccines that were currently available. An inexpensive nebulizer and the procedure for administration of aerosolized vaccine to individual children are here described. If the good results reported from the USSR can also be obtained with this simple method of vaccination by aerosol, it may be possible to carry out mass vaccinations against measles with thousands of nonprofessional personnel and thereby quickly eliminate measles in countries where it is still a serious public health problem.