In 2017, Minnesota battled its largest measles outbreak in nearly 30 years, with 79 cases, most of them Somali-American children in Minneapolis. In a new study, researchers say the outbreak should be a warning about how uniquely vulnerable some immigrant parents may be to anti-vaccine messages.

More than 80 percent of the cases in Minnesota involved unvaccinated Somali-American kids, whose parents had long been the targets of anti-vaccine propagandists, according to the state health department.

The study, published Thursday in the Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report, found that having one or both parents born outside the US was “significantly associated” with a child not being up to date on vaccinations.

“Overall, children with at least one foreign-born parent were 25% less likely to be current on their vaccinations at 36 months than were children born to two U.S.-born parents, after adjusting for maternal race, age, and educational attainment,” the researchers wrote.

They also noted that vaccination coverage rates for kids of immigrants varied dramatically depending on the mother’s birth country, from 78 percent among children born to Central, South American, and Caribbean moms to 44 percent among children born to Somali mothers.

To be clear, vaccine-preventable outbreaks in the US aren’t unique to immigrant communities. And the researchers in Minnesota found some immigrant groups had vaccine coverage rates that were higher than the US average. But immigration status can be a crucial and too often overlooked risk factor, Kristen Ehresmann, director for infectious diseases at Minnesota’s Department of Health, warned.

Minnesota’s 2017 measles outbreak is a case in point. In 2008, anti-vaccine advocates — including the Organic Consumers Association and Andrew Wakefield, a British doctor who falsified data suggesting vaccines are linked to autism — began targeting local Somali Americans who had concerns about autism among their children. The activists saw an opening, offering an explanation when the health department couldn’t provide one.

Vaccination rates plummeted in the community over the next several years, making its members more susceptible to preventable diseases such as measles and mumps. Of the 79 cases in the 2017 measles outbreak, 65, or 80 percent, involved children of Somali descent.

“What this means for public health and providers,” said Ehresmann, “is that they need to recognize parents are not all the same.”

Immigration status and cultural context should certainly be considered when doctors are talking to parents about vaccines, she added. “If you have a child with parents who are born outside of the US, there may be cultural issues, they may have challenges accessing health care, they may have had an experience in their home country that made them pro-vaccination, and you can build on that.” Minnesota learned this lesson too late.