PITTSBURGH Children entering school may be fully immunized according to state requirements, but they may still fall short of federal recommendations, according to a recent study.
The Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP) issue recommendations for childhood immunizations. These are recommendations only; each state adopts its own immunization requirements, said Bradley J. Bradford, MD, lead author of the study. Bradford is chairperson of the department of pediatrics, Mercy Children's Medical Center, Pittsburgh.
For example, Pennsylvania, which was the site of Bradford's study, requires children to have received three doses of diphtheria, tetanus and polio vaccines and one dose of measles-mumps-rubella (MMR) vaccine by school entry. These requirements are markedly lower than those of the ACIP and AAP, which, at the time of the study, advised that children receive at least five doses of diphtheria-tetanus-pertussis (DTP) vaccine, four doses of polio vaccine, four doses of Haemophilus influenzae type b (Hib) vaccine and one dose of MMR.
Bradford and his colleagues found that although all of the children in their study were fully immunized according to state requirements, fewer than half met the ACIP and AAP recommendations.
For the study, Bradford examined the medical records of 281 children entering school in two Pennsylvania school districts during the 1990-1991 school year. The researchers looked only at the number of doses received; they did not look at the timing of the doses. Therefore, some children who were fully immunized may have received some doses at incorrect intervals.
All of the 281 children evaluated satisfied state requirements for school entry; however, 159 (57%) were considered under vaccinated according to the ACIP and AAP recommendations.
Altogether, 114 children (72%) were missing at least one dose of DTP vaccine; 89 (56%) were missing at least one dose of Hib vaccine; and 65 (41%) were missing at least one dose of polio vaccine.
One-half (79) of the 159 under vaccinated children were lacking doses of only one vaccine, most often Hib or DTP. Of these, 25% (39 children) were missing a dose of Hib about one-third (32%) had received no doses at all and 22% (35 children) were only missing the fifth DTP dose. Three percent of the children (five) were missing only polio vaccine.
Among the 80 children who were missing doses of multiple vaccines, 19% (30 children) were missing both DTP and polio; 13% (20 children) were missing DTP and Hib; and a single child was missing polio vaccine and Hib. Eighteen percent (29 children) were missing doses of all three vaccines.
Bradford and his colleagues then contacted the parents of 237 children (84%) to determine why the children were under vaccinated. The parents were contacted by telephone and, if appropriate, asked to identify the reasons their children had not received the full immunization series recommended by the ACIP and AAP. Parents were able to select more than one reason from a list.
By far, the most common reason was that the parents did not know a vaccine was needed (75 parents; 58%). The next most common reasons were that the provider did not offer the vaccine; the cost of the vaccine; and fears of adverse reactions, all of which were chosen by four parents (3%).
Rounding out the list of reasons for failure to vaccinate were "an intercurrent infection" (three parents, 2%); "mobility" (two parents, 2%); "noncompliance," (two parents; 2%); "no access to a facility" (one parent, 1%); and "religious or personal objection" (one parent, 1%). No parents chose "medical contraindication" as a reason for under vaccination.
Virtually all of the children had an opportunity to be vaccinated. Of the children who were under vaccinated, 96% had seen a physician within the previous year; nearly two-thirds (65%) had seen a physician within the previous six months.
"In a rather homogeneous population of primarily white, higher income families, all of whom had some form of health coverage, we found a majority of the students to be not fully immunized according to recommendations for age despite school entrance and a recent visit to their physician," Bradford and colleagues concluded. "This was true despite the fact that under/unvaccinated children typically come from minority populations with lower income levels whose access to health care is hampered and coverage for costs absent or inadequate."
The study suggests that parents are compliant with pre-school entry physicals and immunization requirements if they know what is needed.
"The reasons for the lack of immunization were that the physicians withheld immunizations and parents were not educated," said Bradford, who is also the president of the Pennsylvania AAP chapter. "Most parents did not know that more immunizations were needed. It is up to the providers to educate parents."
For more information:
- Bradford BJ, Benedum KJ, Heald PA, et al. Immunization status of children on school entry: area analysis and recommendations 1991. Clin Pediatr.1996; 35:237-42.
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