Immunity to measles in a large population of varying age. Significance with respect to vaccination
H. Braunstein, S. Thomas and R. Ito
Department of Laboratories, San Bernardino County Medical Center, CA 92404.
During a measles outbreak, 660 hospital employees of widely varying ages
were screened for immunity to the disease using an automated indirect
fluorescent antibody technique. Of these 660 employees, 623 indicated their
year of birth; 21 were seronegative and 13 had borderline titers. Of those
born before 1957, 7 tested seronegative and 6 were borderline, while 12 of
those born between 1959 and 1964 were seronegative and 3 were borderline.
There are several possible reasons for these findings. It is concluded that
mass immunization of high-risk populations during outbreaks, while
effective, is difficult to justify scientifically because only a small
percentage of subjects are not immune. If facilities permit, mass screening
during outbreaks may be feasible. Preferably, continuous screening and
vaccination of susceptible high-risk employees could be performed. Our
study also does not validate exclusion from immunization programs those
born prior to 1957 in view of the fact that both seronegativity and disease
occur in this age group with significant frequency.
