Persistent worries about the safety of childhood vaccines could undercut national immununization efforts, a new survey finds.
Nearly a year after Andrew Wakefield's study linking vaccines and autism
was famously discredited, the debate between parents and pediatricians over vaccine safety rages on. With Rep. Michelle Bachmann's claims about the HPV vaccine's link to "mental retardation"
stirring the pot, it's a debate that is unlikely to resolve itself anytime soon.
Meanwhile, parents are still uneasy about the frequency and number of shots children are expected to receive in the first years of life. Although complete vaccine refusal is uncommon, many parents are choosing to forgo or delay certain vaccines
until their children are older. Others follow the schedule that pediatricians recommend, but are "on the fence" about doing so, according to a new survey conducted by researchers at the University of Michigan.
The trend of parents adopting alternative schedules is only likely to increase as anti-vaccine attitudes gain traction among parents, the researchers reported online October 3, 2011, in the journal Pediatrics
. Parents' concerns persist despite substantial evidence showing that vaccines are largely safe
and that early, routine vaccination is the best way to protect children from infectious disease
The survey found that 1 in 10 parents of children 6 years and younger don't follow the immunization schedule
established by the Centers for Disease Control and Prevention (CDC), opting instead for a modified version in which some vaccines are deferred or skipped. One-third said they switched from the recommended schedule to an alternative one because it "seemed safer." In many cases, parents used their own vaccine schedule or one recommended by a friend.
The finding reflects a common fear among parents—that childrens' immune systems can be "overwhelmed" by the 25 inoculations they receive in the first 15 months of life. This is the basis of the "alternative vaccine schedule" promoted by Robert Sears, MD, MD, FAAP, author of the popular titles The Vaccine Book and The Autism Book. In the recent Pediatrics study, 8% of parents reported following Dr. Sears' schedule.
The American Academy of Pediatrics has called the celebrity pediatrician's schedule "a misrepresentation of vaccine science
that misinforms parents." In a fact sheet for parents, AAP explains that the timing of vaccines
under the CDC-backed schedule is calibrated based on infants' vulnerability to contagious diseases and the ability of their immune systems to make the most use of live virus contained in vaccines.
While delaying or "spreading out" vaccines yields no clinical benefits, it also puts kids and communities at risk, experts say. Even a slight departure from the schedule has consequences: research shows children who miss one or more of the recommended vaccines are 22 times likelier to contract measles and 6 times likelier to contract pertussis than children who receive all their shots.
Outbreaks of childhood diseases are also increasing, in part because more parents are opting not to vaccinate, according to the study. Measles—a disease virtually eradicated in the late 1990s thanks to an effective vaccine—reached a 15-year high in 2011
, the CDC reported. Of the 118 patients who contracted the illness from January to May of this year, 89% were unvaccinated.
"Small decreases in vaccine coverage are known to lead to dramatic increases in the risk of vaccine preventable disease outbreaks," said study author Amanda Dempsey, MD, PhD, MPH, an assistant professor and researcher at the University of Michigan's C.S. Mott Children's Hospital. "Not following the recommended schedule leaves kids at risk for these diseases unnecessarily," she added.
Even parents who do follow the guidelines expressed concerns about timing. Approximately 1 in 5 believe it's safer to delay vaccines until children are older, and 1 in 4 doubt that the immunization schedule recommended by experts is the best one to follow. These parents are considered "at risk" for switching to an alternative schedule, according to the study.
The authors stressed the need to develop education that targets this group—and quickly. "More resources need to be devoted to finding ways to successfully change where attitudes are going," said Dr. Dempsey. "Clearly this problem is not going to go away, and our data suggests it will actually get worse over time."
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