Measles immunization. Successes and failures
A. S. Yeager, J. H. Davis, L. A. Ross and B. Harvey
As a result of a large outbreak of measles, measles hemagglutination
inhibition (HI) titers were measured in 465 immunized children. Titers of
less than 1:4 were found in 14.6% of children immunized at 12 months of age
as compared to 5.2% of those immunized at 13 months of age or later.
Measles antibody titers were higher in the mothers of seronegative children
who had been immunized at 11 or 12 months of age than in the mothers of
seroposotive children. Measles HI titers of 1:4 or more were present in 94%
of children immunized at 13 months of age or later between 1962 and 1964.
The findings suggest that vaccine failure and not waning antibody accounts
for the majority of titers of less than 1:4 in immunized children.
Reimmunization programs should be considered for those who were immunized
before 13 months of age.
