Nearly half of Baltimore's inner-city children fail to receive all the immunizations they are supposed to get by age 2, even though a high percentage have health coverage and visit a family doctor for preventive care, according to a study released yesterday.
Dr. Bernard Guyer, the lead investigator from the Johns Hopkins School of Hygiene and Public Health, said various factors contribute to a trend in which children "miss opportunities" to begin their sequence of childhood immunizations in the first months of life, leaving them unprotected when they are most vulnerable.
Calling the failure baffling, researchers said several factors could explain it: the complexity of immunization schedules, exaggerated fears about vaccinating children who have colds and other minor illnesses, poor recordkeeping by medical offices and records that get lost when families change doctors.
What is clear, Dr. Guyer said, is that efforts to provide universal health coverage will not solve the problem, because most of the families are already covered through Medicaid.
"If we had universal coverage, that would only be the beginning of the battle," Dr. Guyer, chairman of the school's department of maternal and child health, said during a briefing at the South Baltimore Family Health Center in Cherry Hill.
He said public health systems must find a way to store every child's immunization record in a central data bank. Also, he said, agencies such as the Centers for Disease Control and the American Academy of Pediatrics should agree on the medical conditions that warrant postponement of a child's shots.
By law, all children must be fully immunized against such diseases as measles, mumps, rubella (German measles), polio, tetanus, diphtheria and whooping cough by the time they enter grade school. Dr. Guyer said many children fall behind as infants and catch up later.
Public health authorities have widely blamed the measles epidemic that struck Baltimore and many other cities in 1989 and 1990 on low levels of immunization.
For the study, researchers randomly selected 557 children who had reached their second birthday between November 1991 and April 1992. The survey covered 57 low-income neighborhoods.
Information about childhood immunizations was drawn from medical records and interviews with parents.
The study, also conducted by researchers with the University of Maryland School of Medicine and the state and city health departments, appears in this month's issue of the journal Pediatrics.
Among the findings were that:
* 54 percent of the children had received the recommended shots by age 2.
* 70 percent got their first vaccinations on time, but by age 19 months only 13 percent had received all of their immunizations at the recommended intervals.
* Two of the 557 children in the survey had no source of well-baby care. About 75 percent were covered by Medicaid, and 11 percent had no form of insurance.
The Baltimore findings are similar to those in other cities, including Philadelphia and Los Angeles.
Dr. Bernard Abbott, a pediatrician with the South Baltimore Family Health Center, said many doctors delay giving shots to youngsters with minor illnesses because they fear getting sued if the children suffer side effects.
Doctors are confused by the ever-changing immunization schedules and lists of precautions issued by health agencies, he said, and some may be complacent about immunizing children against diseases, such as polio, that they have never seen.