What Washington can learn from past measles outbreaks

Minnesota's prior experiences may inform how Washington should handle their current problem.

measles prevention poster complications
A poster for measles awareness in Minneapolis, MN in 1939City of Minneapolis

Anti-vax groups have, for decades, used debunked research to stoke parents’ fears of the measles, mumps, and rubella (MMR) inoculation, fueling an uptick in unvaccinated children in the United States. As a result, Washington, Texas, and New York are now struggling to keep measles at bay. To stop the virus from re-establishing its foothold in the U.S., we need to figure out how to reach parents with the clear message that vaccines are safe. Public health advocates don’t seem to be getting through, so Washington State officials are now seeking advice from across state lines.

Back in 2011 and again in 2017, measles outbreaks hit the Somali community living in Minnesota. The outbreaks were the result of dangerously low vaccination rates that had been prompted by fears of autism, and enabled by state laws allowing personal belief exemptions. In other words, they were a lot like the current outbreaks in the Pacific Northwest.

In Clark County, where the vast majority of Washington's measles cases have occured, almost 80 percent of all vaccine exemptions among kindergarteners last school year were due to personal belief, according to Washington State Department of Health data. Those exemptions brought their vaccination rate down to less than 85 percent. Now, the county has 64 confirmed measles cases as of February 22.

That’s why the Washington State Department of Health met with their counterparts in Minnesota last week to discuss which tactics proved effective when the Minnesota Department of Health (MDH) was tasked with containing their own measles outbreaks. Though their successes weren’t unmitigated, they’re one of the few case studies experts can turn to for examples of how to manage these bursts of previously-eradicated disease.

MDH data shows that MMR vaccine coverage of Minnesota-born Somali children started to decline in 2006, when vaccination rates were above 90 percent. Around the same time, Somali-American children were being diagnosed with autism at a higher rate than any other demographic in Minnesota, and parents didn't have answers as to why. Andrew Wakefield, the British scientist who famously published fraudulent research claiming a link between the MMR vaccine and autism, provided what seemed like an explanation. He came to speak to a small group of the parents in Minneapolis, preying on their concerns, and partnered with anti-vax groups which targeted the state's Somali population.

It worked.

By 2011, first-dose vaccination coverage among Minnesota-born Somali children had fallen to just 54 percent, well below the 90-95 percent rate needed for herd immunity.

That year, Minneapolis confirmed 26 cases of measles, its largest outbreak in almost 30 years. About 40 percent of those cases were in Somali-Americans, which elevated concerns the health department already had about falling vaccination rates within the community.

They ramped-up their outreach efforts. MDH partnered with leaders in Minnesota’s Somali-American community; Health officials and trusted religious leaders who not only spoke the language, but were familiar faces within the community, delivered messages that focused on vaccine safety, necessity, and normalization. Daycare providers who predominantly served the community required unvaccinated children to stay home during the outbreak, not wanting to be shut down due to an outbreak in their facilities.

It didn’t work. Vaccination rates fell further, sinking to less than 42 percent by 2014. But it did expose holes in the way the public health system was handling the issue of low vaccination rates.

“We were focusing on concerns related to the vaccine, but their concerns were related to autism,” says Kris Ehresmann, director of the MDH Infectious Disease Division. “The vaccine information didn’t resonate with these parents if we weren’t first addressing their concerns surrounding autism.”

When a second, larger outbreak hit the Twin Cities in April 2017, over 80 percent of the 75 confirmed measles cases were among U.S.-born children of Somali descent. MDH once again worked with Somali-American staff who were both trusted in and familiar to the community. This time, though, their messages not only included scientific studies on the vaccines themselves, but also on prenatal care that introduced accurate vaccine information before a baby was even born. They also disseminated information that discussed concerns surrounding autism alongside other early-childhood issues.

Asli Ashkir was a senior consultant with the MDH during the outbreak. She focuses on children and youth with special health needs, especially autism. She’s also Somali-American.

measles immunization poster
A CDC poster promoting measles immunizationNational Library of Medicine

“They were telling me, Asli, you only know about vaccination,” says Ashkir, as opposed to knowing about the other health concerns parents had. That’s why she thinks the vaccination discussion needs to be embedded within discussions of other childhood illnesses such as asthma, which she found was also a top concern among the parents she spoke with during the measles outbreak.

But misinformation within the Somali community was a fairly easy target. According to Ashkir, many Somali-Americans living in the Twin Cities attend the same mosques, go to the same malls and daycares, and even live in the same apartment complexes. The misinformation in this community was largely spread by mouth, but that isn’t the case in Clark County.

Dr. Alan Melnick, a Clark County-based health officer with the Washington State Department of Health, believes the majority of fear surrounding vaccines in the county can be traced back to misinformation spread through social media.

“Some of it looks really sophisticated and scientific, I don’t blame parents for believing it to be true,” says Melnick. Some misinformation includes screen grabs of sitcoms from the 1960s when measles was common, and claim the virus to be a benign childhood illness that parents shouldn’t be worried about, says Melnick. Other materials falsely link vaccines to autism and seizures.

According to Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, the anti-vaccine groups behind this disinformation started as a fringe movement, but have evolved into a well-oiled machine.

"Now there are over 500 anti-vaccine websites and books that are amplified on social media, and political action committees that lobby state legislators and make it easier to opt out of vaccines," he says. Hotez's daughter has autism, and he says the developmental disorder is still front and center in the anti-vaccine movement. Hotez says search engines and social media platforms should be proactive in blocking misinformation from being seen in the first place, something Pinterest recently took to heart by actively preventing misinformation about vaccines from appearing on their site. So far, they're the only platform to do so.

State governments also need to take the battle online. According to Melnick, Clark County has handled the outbreak by advising doctors on best practices and updating the county’s social media pages with press releases and healthcare advisories, thereby creating more digital content to counter the widespread anti-vax information.

Still, for many, the damage is done. It’s hard to change parents’ minds when they truly believe foregoing vaccines is the healthiest thing for their child.

“For that hardcore group, they will do about anything to avoid vaccination,” says Ehresmann of MDH. The aftermath of the efforts in the Twin Cities prove her right.

Vaccination rates among U.S.-born Somali children living in Minnesota rose to just 58 percent in the months following the outbreak. That number is still far below the rate needed for herd immunity and is 12 percent lower the vaccination rates in 2010, just before the city’s first outbreak. Both Ehresmann and Ashkir say they’ve spoken with parents who immunized their children with first dose MMR vaccines during the 2017 outbreak, but now that it’s over, say they would still consider not vaccinating in the future.

Ashkir believes the vaccination rate among Minnesota’s Somali community peaked during the outbreak and has likely declined since. According to the Minnesota Department of Health, there were two cases of measles in Minnesota last year. “I’m expecting another outbreak at anytime,” says Ashkir.

Melnick says rates of vaccination in Clark County are on the rise since the measles outbreak began last month. But if Minnesota is anything to go by, that peak may trend downwards again.

That’s why Hotez and Ehresmann both say the pro-vaccine voice needs to be as loud and widespread as the anti-vaxxer misinformation. “Right now it’s treated like brushing your teeth,” says Ehresmann. “Nobody is standing on the corner shouting about how important it is to brush your teeth because it’s assumed that everybody does it.”

Washington state introduced legislation shortly after the measles outbreak started in January that would ban personal exemptions for MMR vaccinations for kids who attend public school. Researchers and physicians across the country have declared such legal action is our best bet in achieving herd immunity nationwide. Ehresmann agrees that legislative changes which ban MMR exemptions for non-medical reasons would likely result in more immunized kids, but the solution isn't perfect.

Flaws in the healthcare system allow backdoor personal belief exemptions in states like California, which outlawed such exemptions after a measles outbreak in 2015. A study published last October in the journal Pediatrics found that medical exemptions for vaccinations in California increased 250 percent, from 0.2 percent in 2015–2016 to 0.7 during the 2017–2018 school year. It also reported that some doctors were charging parents a fee to have them write medical exemptions for children, sometimes without an examination.

Still, Hotez says enacting laws that require vaccination would be our best bet in preventing future measles outbreaks, if it could actually happen. “Right now, even with this measles epidemic, I do not feel the political will is there,” says Hotez. “So unfortunately things will get worse before they get better.”

Correction: This article has been updated to reflect the fact that there were two cases of measles in Minnesota last year, not 15, as previously stated. We regret the error.