More than half of all urban children have not received all the immunizations they need by their second birthday, new data from the U.S. Centers for Disease Control suggest.
Although about 95 percent of all children have been fully immunized by the time they enter school, vaccination rates for children by their second birthday have historically been lower.
Both the C.D.C. and the American Academy of Pediatrics recommend that all children receive a full series of vaccines by age 15 to 18 months.
To determine when children become fully immunized, researchers from the C.D.C., in collaboration with state and local health officials, examined the vaccination records of children entering school in tone large cities in 1991. Eventually, records of children in 60 cities will be studied.
According to the study, students in El Paso, 42 percent of whom received the entire recommended series of vaccines by age 2, had a higher vaccination rate than children in any of the other cities studied. In contrast, 10 percent of Houston children received the complete series by age 2, the lowest rate among the cities studied.
The study classified children who received four doses of the diphtheria, tetanus, and pertussis vaccine, three doses of the oral polio vaccine, and a single dose of the measles, mumps, and rubella vaccine by age 2 as meeting vaccination requirements.
Children who received their first vaccines at age 3 months, as recommended by both the C.D.C. and the A.A.P., were three times more likely to be up-to-date at age 2 than those children who received their first vaccine at a later age, the study found.
To boost vaccination levels among preschool-age children, the report recommends that doctors and other health-care professionals adopt more aggressive outreach efforts.
“Each contact with a health-care provider represents an opportunity to educate parents about the recommended vaccination schedule and the importance of completing the schedule on time,” the report concludes.
“Parents of children who begin the vaccination series late should be targeted for intensive education, and greater efforts are needed to track these children to assure they return for follow-up doses,” it states.