Evaluation of an early two-dose measles vaccination schedule.
Vaccination at 6 months of age followed by routine revaccination is recommended when exposure of infants to measles is likely. Dade County, Florida, began this early two-dose schedule during a large epidemic in 1986-1987 (i.e., 22% of cases occurred in infants aged 6-11 months). This schedule was continued routinely in high-risk areas. The effect of an early two-dose schedule on measles prevention in the county was examined by comparing measles vaccination coverage and epidemiology before (1985-1987) and after (1988-1996) the schedule became routine. To assess serologic response, seroprevalence of measles antibody among children aged 4-6 years in 1995 was examined. To evaluate vaccine effectiveness, a case-control study was conducted among preschool-aged children. Among those aged 2 years, vaccination coverage with > or =1 dose increased from 75% to 94% in 1996. The number of annual cases declined, and endemic measles transmission reportedly ended after 1993. Seroprevalence of plaque reduction neutralization antibody (titer > 1:120) among those receiving vaccination according to an early two-dose schedule and a single dose at age > or =12 months was 94% (95% confidence interval: 89, 98) and 98% (95% confidence interval: 95, 100). In these groups, vaccine effectiveness was comparably high. Early two-dose measles vaccination is associated with improved coverage and a comparably high level of humoral immunity and clinical protection as a single dose at age > or =12 months. This strategy can be useful in areas at high risk for measles among infants.
Hutchins
S S
SS
Epidemic Intelligence Service, Division of Applied Public Health Training, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, GA, USA. ssh1@cdc.gov
Dezayas
A
A
Le Blond
K
K
Heath
J
J
Bellini
W
W
Audet
S
S
Beeler
J
J
Wattigney
W
W
Markowitz
L
L
D000914:Antibodies, Viral / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005260:Female; D005431:Florida; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D016015:Logistic Models; D008297:Male; D008457:Measles / Q000276:immunology* / Q000517:prevention & control*; D008458:Measles Vaccine / Q000008:administration & dosage*
D000914:Antibodies, Viral; D008458:Measles Vaccine