Medical Minute: Measles Outbreak

Jessica Fichtel can't understand why her neighbors chose not to vaccinate their kids and, consequently, increased the risk of her son getting measles? 

The Vancouver, Washington, mom struggled every day to keep her then-6-year-old, Kai, alive while he underwent chemotherapy to fight childhood leukemia during the measles outbreak there in 2019. 

"His life would be in grave danger if he would have been exposed to measles and contracted it," Fichtel said. 

During the 2019 outbreak, measles spread rapidly, reaching 71 cases in four months. At the time, health officials said 78% of children in Clark County, where Vancouver is located, were vaccinated — well below the 95% threshold that the CDC identifies as crucial for protecting a community from measles. 

Fichtel said she personally knew of families in her neighborhood who chose not to get their children the measles, mumps and rubella (MMR) vaccine — some of whom played with Kai, who couldn't be vaccinated himself because of his compromised immune system. 

"There's a lot of rage, a lot of anger" at those people, Fichtel said. "I just can't wrap my head around why you wouldn't do it unless you had the very best reason, right?" 

Data shows parents across the country have reason to be concerned. A CBS News investigation examined data from tens of thousands of public and private schools in 19 states and communities that make that information available to parents and the public. 

Our investigation has identified at least 8,500 schools where measles vaccination rates among kindergartners are below that 95% threshold that the CDC identifies as crucial for protecting a community from measles. 

A nationwide decline in vaccinations  

The falling school-age vaccination rates are alarming scientists and doctors across the country, many of whom are concerned more people could be at risk of being infected with measles. Earlier this month, cases were identified in Philadelphia, and 82 children in Ohio contracted measles in 2022. 

"I think it's concerning to me as a human being," said Penn State University biologist and infectious disease researcher Matt Ferrari. "It also has a population-level consequence. The more individuals that are around who are unvaccinated, the more potential there is for disease to spread and to establish transmission that will give rise to outbreaks that will stick around for a long time." 

Communities need high vaccination rates to maintain herd immunity and prevent outbreaks, Ferrari said. Herd immunity protects even those who can't get vaccinated, like Kai, because enough people are protected that diseases won't spread in the first place. 

"The vaccinated around you act as a shield and reduce your risk," Ferrari explained. "Herd immunity, simply put, is just the indirect protection to a non-vaccinated person of being surrounded by vaccinated people. Those vaccinated people act like a shield." 

In many communities, fewer people are serving that protective role, according to the CDC data analyzed by CBS News. About 93% of kindergarteners in the U.S. were vaccinated against measles during the 2021-2022 school year, down from 95% just a few years prior. 

Many of the schools involved in the Clark County, Washington, outbreak had vaccination rates far lower. Of the 16 schools and day cares where health officials said cases were found, nine had vaccination rates below 90%. Some were as low as 50%. 

Across the country, another measles outbreak  

The same year as Vancouver's measles episode, New York City had its own measles outbreak. Before it was over, 649 people contracted measles and dozens were hospitalized. 

The vaccination rate had dropped in New York, too. Officials there were so concerned that they ordered all unvaccinated people to get the vaccine or face fines. 

The city's public health commissioner says enforcement of vaccination requirements, coupled with public education campaigns, helped stop the outbreak after 11 months. 

"I think what we see is that we have to use every tool in our toolkit," said NYC Health Commissioner Dr. Ashwin Vasan. "Sometimes requirements and mandates can work in certain environments and in certain times, particularly in outbreaks and in emergencies. But we have to make that also a part of an ongoing dialog, an ongoing set of conversations with the communities that have the lowest vaccination rates." 

And though New York City's childhood vaccination rates went up immediately after the outbreak, CDC data shows they're down to about 96.6%, compared to 98.8% in 2018. While that decline may not sound like much, Vasan said he's "worried about the trend if it continues in that direction." 

"You are seeing little pockets … [that] correlate with communities that have lower vaccination rates," Vasan said. "And that, I think in part, is a product of a very well-funded and very well-targeted campaign of anti-science, anti-vaccine messaging that targets communities that can be susceptible." 

Community problems, community solutions  

Rates are declining for a variety of reasons: political influences, misinformation, mistrust in government and fear of vaccines. All play a role, experts told CBS News. 

"We now have a misinformation superhighway, which is social media, and frankly, entirely unregulated and unfettered access to [vaccine misinformation]." Vasan said. "You can get pretty sophisticated in the ways in which you target misinformation to certain communities using cultural touch points that really reach into communities that often are left behind or that struggle to build trust with government." 

The share of kindergarteners who are unvaccinated has ticked up in recent years, according to CDC data. 7% were unvaccinated during the 2021-2022 school year. 

Less than half of those children — an estimated 2.6% — had exemptions, which allow them to attend school without the required vaccines because of medical or religious reasons, or, in some states, for so-called "philosophical reasons." The remaining 4% were either non-compliant or completed their required vaccines later in the school year, after the data was recorded. 

Five years ago in Maine, the numbers of parents claiming religious exemptions climbed so high, half of the schools were below the 95% herd-immunity threshold. Churches banded together to try to change minds. 

"When it comes to public health, for us, it didn't seem radical at all to say, in this instance, the way we love our neighbor is to get vaccinated, to protect the vulnerable, to protect the marginalized, the young, the very old, the sick," said Rev. Jane Field, executive director of the Maine Council of Churches. 

The council lobbied lawmakers to pass a law that eliminated the religious exemption. The share of schools below herd immunity has fallen from 50% to 20%, and exemptions have fallen to less than 2%. "We came alongside medical organizations, pediatricians' organizations, teachers' organizations," Field said. "It was a broad, broad-based coalition of people that joined that coalition to say, here's the right thing to do." 

More people did get vaccinated during Clark County, Washington's 2019 outbreak. But a few years later, the vaccination rate is near what it was before the outbreak, and many remain unprotected. Nearly two-thirds of schools across the state have vaccination rates below 95%, according to data analyzed by CBS News. That's nearly 53,000 students in schools there that aren't fully protected. 

That leaves children like Kai at risk. 

"I just can't wrap my head around why you wouldn't get vaccinated," Fichtel said. "Why wouldn't you do it for the 5-year old kid who if he were to get measles, he's going to die?"