Susceptible state
In total, only 78.5 percent were fully vaccinated against the measles virus with the MMR vaccine (measles, mumps and rubella). That is well below the goal of 95 percent vaccination coverage, which is the level needed to prevent the virus from spreading in communities. With the high level of exemptions, the maximum MMR vaccination coverage the state could achieve is only about 85 percent.
Measles outbreaks have wreaked havoc in several places inside and outside the United States. But so far, Idaho has been quiet, with just nine cases detected since the beginning of 2026. Those cases occurred in three counties and all involved people who were unvaccinated or had unknown vaccination status, according to a state measles tracking site.
However, it is unclear whether cases can go undetected in the state. Last August, the state reported three cases, including two cases in two neighboring counties to the north. Health officials noted at the time that there was no clear link between the two cases. “Without any link between these two confirmed cases in northern Idaho or travel outside of their communities, it is reasonable to suspect that there is more measles circulating,” Christine Hahn, state epidemiologist and medical director of DHW’s Public Health Division, said at DHW. a press release on August 20. “As we have seen in other states in the country, cases can begin to multiply rapidly.”
For now, no cases have been identified in connection with the airport case, but health officials are advising residents to get the MMR vaccine, two doses of which are 97 percent effective, and that protection is considered lifelong.
“The MMR vaccine is extremely effective at preventing measles and is routinely recommended for children 12 to 15 months of age, with a second dose between 4 and 6 years of age,” the health department said.
