Investigation of a measles outbreak in a fully vaccinated school population including serum studies before and after revaccination.
A measles outbreak in early 1989 among approximately 4200 students at a high school and two intermediate schools in suburban Houston, TX, was investigated to evaluate reasons for vaccine failure and to predict the efficacy of a booster dose of measles vaccine. Seventy-seven cases occurred (71 at the high school, 6 at intermediate schools; attack rate, 3.2 and 0.3%, respectively). Vaccination in the first year of life an 13 to 14 years since last vaccination were independent risk factors for being a case. Forty-three (18%) of 239 sera collected from students just before revaccination during the outbreak were negative by enzyme immunoassay; a neutralization assay confirmed these 43 lacked antibody predicting protection against measles infection. Of 43 enzyme immunoassay-negative students 24 gave another blood sample 9 to 10 months after revaccination. Revaccination appeared to reduce the portion of all students with neutralization titers predicting susceptibility to measles illness with rash from 7.9% to 3.0% and left the portion predicted to be susceptible to illness without rash unchanged (45%).
Matson
D O
DO
Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030.
Byington
C
C
Canfield
M
M
Albrecht
P
P
Feigin
R D
RD
D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood; D016009:Chi-Square Distribution; D004196:Disease Outbreaks; D004198:Disease Susceptibility; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D008457:Measles / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control; D009500:Neutralization Tests; D015995:Prevalence; D012307:Risk Factors; D012574:Schools; D012621:Seasons; D016036:Seroepidemiologic Studies; D013383:Suburban Population; D014611:Vaccination
D000914:Antibodies, Viral