Despite high vaccination levels, measles outbreaks continue to occur among vaccinated adults. In response, new guidelines call for two doses of measles vaccine. To determine seroprevalence and response to vaccination in seronegative persons, we tested serums from 256 college athletes at a Maryland State college by enzyme-linked immunosorbent assay, vaccinated seronegatives, then re-tested vaccinees. High school records were obtained for persons seronegative to measles. Of 256 students, 53 (21 percent) were seronegative to measles alone, 13 (5 percent) were seronegative to rubella alone, and 5 (2 percent) were seronegative to both. Among those seronegative to measles, 86 percent had previously received a dose of measles vaccine. After vaccination, 37 persons initially seronegative to measles and 9 seronegative to rubella were 97 percent and 100 percent seropositive, respectively. The high measles seroconversion rate suggests that the two-dose vaccine schedule should effectively control campus measles outbreaks and, if given as measles-mumps-rubella vaccine, will also improve immunity to rubella and mumps.
