The authors have developed enzyme immunoassay (EIA) for detecting anti
measles antibodies in the serum and compared it to routine methods. Pr
eparation and purification of measles virus antigen used in EIA and op
timal conditions of the reaction are described. Results of the routine
methods and those of EIA correlated. EIA was used to determine titers
of antimeasles antibodies in the sera of vaccinated children. 3-4 yea
rs after the vaccination the antibodies were undetectable in the sera
of 23% of children.