Measles outbreak in a fully immunized secondary school population
New England Journal of Medicine
Gustafson TL, Lievens AW, Brunell PA, Moellenberg RG, Buttery CM, Sehulster LM
A measles outbreak occurred among teenagers in Corpus Christi, Texas in the spring of 1985, although vaccination requirements for school attendance had been fully applied. Serum samples from 1806 students in two secondary schools were obtained eight days after the start of the first case. Only 4,1% of these students (74 out of 1806) lacked measles-detectable antibodies based on the enzyme-linked enzyme test and over 99% had registered vaccinations with live measles vaccine. Stratified analysis showed that the number of vaccine doses received was the most important predictor of the antibody response. The ninety-five percent confidence intervals of seronegative rates were 0 to 3,3% for students who had received two previous doses of the vaccine, compared with 3,6-6,8% for students who had received only one dose. single. After the survey, none of the 1732 HIV-positive patients contracted measles. Fourteen of the 74 seronegative students, all vaccinated, contracted measles. In addition, three seronegative students seroconverted without showing any symptoms. We conclude that measles outbreaks can occur in secondary schools, even when more than 99% of students have been vaccinated and over 95% are immune.