Small reductions in childhood measles vaccinations in the United States would produce disproportionately large increases in the number of measles cases and in related public health costs, according to a new study by researchers at the Stanford University School of Medicine and Baylor College of Medicine.


A 5 percent drop in the number of children ages 2 to 11 inoculated against the measles, mumps and rubella would triple the number of annual measles cases in this age group, the study found. The MMR vaccine is an inoculation against the three diseases.

The additional measles cases would increase annual public health expenditures by at least $2.1 million, or $20,000 per case of measles.

The study was published July 24 in JAMA Pediatrics.

“We focused on measles as a case example of the effects of declining vaccine coverage because it is highly infectious,” said Nathan Lo, the study’s lead author and an MD-PhD student at Stanford. “It’s likely to be the first infectious disease causing outbreaks if vaccination declines.”

Lo said he hopes the findings will be considered by state legislators making decisions about vaccination policy.

“I think our study is a wake-up call for what we can expect in the coming months and years as vaccine coverage rates continue to decline in the 18 states that now allow non-medical or philosophical belief exemptions,” said senior author Peter Hotez, MD, PhD, dean of the National School of Tropical Medicine at Baylor.

Across the country, several regions are near the threshold of 90 to 95 percent vaccine coverage needed to prevent measles outbreaks. The new study predicts a sharp rise in measles cases if vaccination further declines.