May 5, 2010 -- In 2008, 39% of parents refused or delayed giving at least one routine vaccine to their children, up from 22% just five years earlier, the CDC reports.
Despite the delays, which widen the critical period in which kids are most vulnerable to vaccine-preventable diseases, the percentage of kids who got all their basic vaccinations went up to 76% from 73%, says Lance E. Rodewald, MD, the CDC's director of immunization services.
The data come from the National Immunization Survey, the CDC's telephone survey of the parents of some 9,000 toddlers ages 19 months to 35 months.
Many of the parents who delayed or refused vaccinations worried about whether the vaccines were safe or effective:
- 27% said too many shots were recommended.
- 26% questioned whether vaccines really worked.
- 25% cited worries that vaccines might cause autism.
- 24% worried about side effects.
Forty-four percent of those who missed a vaccination did so because their child was sick at the time of the scheduled vaccination. And there were a lot of other non-safety reasons for delay, Rodewald says.
Rodewald says 20% of parents who delayed their child's vaccination did so because the vaccination appointment was inconvenient. Another 17% said they simply missed the appointment. Other non-safety issues included not having transportation or not being able to afford the cost of the vaccination.
And Rodewald also notes that kids were more likely to miss a vaccination in 2008 than in 2005 because four more multi-dose vaccinations were added to the schedule.
The good news, Rodewald says, is that only about 1% of parents refuse all vaccination for their kids -- a rate that hasn't changed much.
The bad news, he says, is that for whatever reason, more parents are delaying vaccination and the fraction of parents who refuse or delay at least one vaccination for their child went up,
"We worry about delayed vaccination, because it increases the length of time a child is unprotected," Rodewald tells WebMD. "The schedule is designed the way it is because most of the morbidity and mortality from vaccine-preventable diseases occurs at the younger ages."
Parents' Vaccine Beliefs
When CDC researchers probed what parents thought about vaccines, they turned up some interesting data.
When asked if they believed that vaccines are necessary to protect children:
- 96% of parents who did not delay or refuse vaccination agreed.
- 95% of parents who delayed vaccination agreed.
- 88% of parents who refused at least one vaccination but did not delay getting others agreed.
- 70% of parents who refused at least one vaccination and delayed at least one other agreed.
"Even among vaccine refusers, it's not like zero percent believe in vaccination," Rodewald says.
Some parents feel it's not necessary to vaccinate their child because so many other children are vaccinated. But this so-called "herd immunity" does not protect individual kids.
"Parents who do that are putting their child at risk and they are putting their peers and neighbors at risk as well," Rodewald says.
CDC researcher Philp J. Smith, PhD, reported the preliminary survey findings at the Pediatric Academic Societies meeting held May 1-4 in Vancouver, British Columbia.