MONDAY, March 1, 2010 (HealthDay News) -- Although most American parents vaccinate their children, many are concerned about the safety of vaccines and some choose not to have their children protected from potentially deadly diseases, a new study found.
Researchers at the University of Michigan found that while 90 percent of parents say vaccines are a good way to protect their kids, and 88 percent follow their doctor's vaccination recommendations, 54 percent are worried about serious side effects.
"Parents' hesitation about vaccines has, in some cases, led them to postpone vaccinations for their children," said lead researcher Dr. Gary L. Freed, director of the Child Health Evaluation and Research Unit at the University of Michigan Health System. "The study found that 12 percent of parents have refused at least one vaccine that their children's doctor recommended."
"When parents refuse vaccines, they place their child at risk for potentially life-threatening vaccine-preventable diseases," Freed added.
The study findings were published in the March 1 online edition of Pediatrics.
For the study, Freed's team collected information from 1,552 parents on their attitudes about vaccines. The survey was part of the CS Mott Children's Hospital National Poll on Children's Health.
It found that almost 12 percent of parents have refused to have a child vaccinated with at least one vaccine recommended by their doctor. The vaccines most often shunned were newer ones, including those for varicella (chickenpox), which 32 percent refused, and meningococcal conjugate, which prevents diseases caused by meningococcal bacteria and was declined by 32 percent of parents. Meningococcal bacteria can infect the blood, spinal cord and brain and can be fatal.
In addition, almost 57 percent of parents rejected the HPV (human papillomavirus) vaccine, which is typically given to females before they become sexually active to help protect them from cervical cancer.
Freed's group also found that one in five parents still believes vaccines cause autism, even though this notion has been repeatedly discredited by scientific research. Women are more likely than men to believe that vaccines cause autism, the study found.
The theory that vaccines cause autism is particularly high among Hispanic parents, although they are more likely not to refuse vaccinations for their children.
Parents' concern that some vaccines may cause autism is particularly disturbing, Freed said. "All reputable evidence on this issue fails to show a link between vaccines and autism, but it appears current public health education efforts on this issue have not yet satisfied many parents' concerns," he said.
Last month, the original article that purported to show a link between autism and the measles-mumps-rubella vaccine was retracted by The Lancet the journal that published it in 1998, because it was based on false data, Freed noted.
Dr. Paul A. Offit, director of the Vaccine Education Center and chief of infectious diseases at the Children's Hospital of Philadelphia, said the growing number of people concerned about vaccine safety was predictable.
Before the introduction of vaccines, disease rates were high, Offit said. "Vaccines weren't available -- people were scared of diseases, and the minute vaccines came on the market they were quick to give them. And the major killers of children were brought low," he said.
But today's parents didn't grow up with these diseases, Offit pointed out. "If you believe, as I do, that people are compelled by their fears, [then] as diseases rates diminish, the fear of disease decreases and the concern about vaccine side effects, real or imagined, increases," he said.
However, Offit pointed out that outbreaks of diseases such as measles can occur in communities where vaccination rates are lower. "The fear of vaccines is not a theoretical problem any more. It's a real problem," he said.
If that fear persists, vaccine rates could drop to the point where serious diseases would make a comeback, and then vaccine rates would go back up, Offit said.
Another vaccine expert, Dr. Marc Siegel, an associate professor of medicine at New York University, said one problem might be that children are getting too many vaccines now, 32 in all.
"If we are having this problem, maybe we need to evaluate which are the most important vaccines and those are the ones we better push for," he said.
All the vaccines are essential, Siegel said, "but we need to justify every vaccine."
To learn more about vaccines, visit the U.S. National Library of Medicine.