Study: Vaccination rates don't increase with risk of catching disease

According to a study presented this week at the annual meeting of the Pediatric Academic Societies, people are not necessarily more likely to get vaccinated when the risk of catching a disease is high.

Elizabeth R. Wolf led a team of researchers in comparing rates of infant vaccination with the diphtheria, tetanus and pertussis vaccine prior to and during a pertussis epidemic in Washington state. No difference in vaccination rates was found.

"We have always assumed that when the risk of catching a disease is high, people will accept a vaccine that is effective in preventing that disease," Wolf, the Ruth L. Kirschstein National Research Service Award Fellow in General Academic Pediatrics at University of Washington' Seattle Children's Research Institute, said. "Our results may challenge this assumption. We hypothesized that a whooping cough epidemic would result in more parents getting their children immunized against whooping cough. But compared to a time before the 2011-2012 whooping cough epidemic in Washington state, there was no significant increase in receipt of whooping cough vaccines for infants during the epidemic."

Washington state reported a pertussis epidemic from Oct. 1, 2001, through Dec. 31, 2012, with infants hit the hardest.

"Vaccination rates in the U.S. are still below public health goals," Wolf said. "We don't fully understand what improves vaccine acceptance. This study found no significant increase in vaccination coverage statewide during the 2011-2012 pertussis epidemic. This finding may challenge the assumption that vaccine acceptance uniformly increases when risk of disease is high."