Nearly 70 percent of doctors surveyed nationally for the study said that parent worries have risen recently, and more than a third of the physicians reported their own concerns had also increased.

That increase in concern has translated into action, the survey also found. More than 90 percent of pediatricians and 60 percent of family practitioners surveyed reported that at least one parent had refused to allow their child to receive a particular vaccine in the past year. And up to a third of family physicians and 12 percent of pediatricians said they did not recommend particular vaccines to parents either routinely or occasionally.

UMHS researchers performed the survey of nearly 750 randomly selected pediatricians and family practitioners across the United States in cooperation with the federal Centers for Disease Control and Prevention (CDC). The results are being presented today at the joint meeting of the Pediatric Academic Societies and the American Academy of Pediatrics in Baltimore.

"Concerns regarding vaccine safety are increasing, and physicians need to be aware of this concern and be knowledgeable about the facts," says Gary L. Freed, M.D., M.P.H., Director of General Pediatrics and the Child Health Evaluation and Research (CHEAR) Unit at UMHS. "There's a significant amount of misinformation and rumor about vaccines. The more we take this issue seriously, the better job we'll do of ensuring immunization and preventing disease."

For three years, Freed and his colleagues have been the only group in the nation funded by CDC to regularly study current vaccine issues for the CDC's National Immunization Program. The new results come from a survey that asked physicians about their patients', and their own, attitudes and actions regarding vaccine safety in general and specific vaccines whose safety has been questioned.

The new findings, Freed says, point to a troubling trend that may put individual children and entire populations at risk for outbreaks of preventable diseases such as chicken pox, measles and hepatitis B. And it points to the need for better education of physicians and the public about vaccine safety and the risks of not vaccinating children.

"Vaccines prevent more disease in the U.S. than any other health intervention, and the risk of the diseases prevented by vaccination far outweighs any risk from any vaccine," says Freed, a professor of pediatrics in the U-M Medical School.

He notes that many of today's parents and physicians don't remember the time when polio and other diseases threatened millions of children, and take for granted the disease-preventing effect of vaccination programs. This may have led to a lower tolerance for even a rumored, much less proven, risk from a vaccine.

The study was designed to assess the impact of several vaccine recalls and well-publicized rumors from recent years. In 1999, a new vaccine against rotavirus was pulled from the market after reports that a small number of infants vaccinated against the gastrointestinal disease-causing virus developed intussusception, or bowel blockages.

Also in 1999, the federal government and the American Academy of Pediatrics recommended that hepatitis B vaccine for newborns be postponed until 6 months of age until its manufacturer could remove the preservative thimerosal, a mercury-containing chemical that had been used for decades.

Though there was no proven risk from thimerosal, the recommendation was made on the basis of public concern and precaution.

Meanwhile, rumors and speculation have grown in recent years about health risks -- ranging from autism to Sudden Infant Death Syndrome (SIDS) -- allegedly posed by vaccines against chicken pox, or varicella; diptheria, or DTP; measles, mumps and rubella, or MMR; and other diseases.

Skeptical or anti-vaccination information on the Internet and in the media has also fed fears and misconceptions about the effectiveness of vaccination or the need to have children vaccinated.

The U-M study, whose results will be presented in several sessions by Freed and CHEAR Unit research investigator Sarah J. Clark, M.P.H., looked at specific parent and physician concerns and actions relating to all these recent developments.

For example, a third of pediatricians reported hearing parental concerns about autism or multiple sclerosis risks from vaccination. One quarter of family physicians and a third of pediatricians said parents expressed worries that new vaccines aren't fully tested and that they should wait before having their child inoculated. About a sixth of both types of physicians reported that parents were worried that additives in vaccines may not be safe.

Many of the doctors themselves said the rotavirus and thimerosal incidents had increased their own concern about vaccine safety, as well as that of their patients' parents. Just over a third of all physicians said the rotavirus vaccine recall had increased their own concern, and a quarter said it had increased parent concern.

Doctors in the survey who reported their concern had grown were much more likely to believe that further research on vaccine safety was warranted by the recent events.

Family practitioners were more likely than pediatricians to believe that more research was needed, but a majority of both groups want more research to be done on the potential for neurologic effects such as autism, on the safety of newly introduced vaccines, and on vaccine additives.

In the meantime, the study suggests that a sizeable minority of physicians -- 21 percent of family physicians and 12 percent of pediatricians -- are occasionally or routinely refraining from recommending certain vaccines to some or all of their patients. This was true for nearly a third of family physicians when it came to the relatively new varicella vaccine, but even a very small number of physicians reported recommending against the DTP, polio and hepatitis B vaccines.

As a result of their study, Freed and his colleagues recommend that all physicians should give parents the Vaccine Information Statements (VIS) that are available from the CDC to help them understand known side effects and low-level risks from vaccines. Their results showed that 92 percent of pediatricians but only 77 percent of family physicians provided a VIS at every vaccination visit.

But, they caution, physicians need to be sensitive to the fact that parents may express concerns about rumored risks not found on the VIS, and need to educate themselves about the information available to address those worries.

Still, Freed says, worried parents and physicians alike should remember the alternative to vaccination: outbreaks of potentially fatal or crippling diseases that once plagued America's children but that are nearly wiped out or could soon be.

According to the CDC, immunizations have reduced vaccine-preventable infectious diseases in the United States by more than 95 percent, and have had a dramatic impact on reducing childhood illness and death.

What's more, Freed says, the knowledge that there is a tested system in place to monitor for adverse effects from vaccines and respond to suspected risks should also provide comfort. The CDC and the Food and Drug Administration (FDA)cooperate to run the Vaccine Adverse Event Reporting System (VAERS).

"Recent events like rotavirus and thimerosal have shown that the vaccine monitoring system takes vaccine safety questions seriously, no matter how small the risk or the incidence, and that public health authorities take action so that we can all be sure that vaccines are safe," he explains. "This constant vigilance and low tolerance for safety issues should reassure everyone." - By Kara Gavin

[Contact: Kara Gavin]

01-May-2001