It all started at the happiest place on Earth.
Of the 9 people who came down with measles last month, the only thing they had in common was a visit to Disneyland or Disney California Adventure Park.
For one father, the recent comeback of the disease, which was officially eradicated from the US more than a decade ago, hits close to home. His son, 6-year-old Rhett Krawitt, has leukemia. He’s currently in remission, but he’s still very vulnerable to infections and can’t be vaccinated against measles.
“I respect people’s choices about what to do with their kids, but if someone’s kid gets sick and gets my kid sick, too, that’s a problem,” the father, Carl Krawitt, told The New York Times. Four years of chemotherapy means Rhett’s immune system is shot, at least for the time being. Rhett isn’t the only vulnerable one — other children, including some at his school, can’t be vaccinated because they are allergic to a specific component of the vaccine or have another medical condition.
In a very public bid for his son’s safety, Carl asked the superintendent of the Marin County school district where his son goes to school to make vaccinations a requirement for all students.
Protecting The Most People Possible
While the proposal may sound stringent, it’s the basis of herd immunity, a concept that’s informed over half a century of public health policy and has helped eradicate dozens of once-deadly diseases, from diphtheria and measles to mumps, rubella, polio, and smallpox.
Herd immunity works like this: Vaccinated people can’t get sick. This makes spread of the disease nearly impossible within a mostly-vaccinated population — a rogue sick or unvaccinated person like Rhett will likely only come into contact with other vaccinated, or protected, people who won’t get the infection, therefore can’t pass it on to others. The virus is stopped dead in its tracks.
If you were to imagine herd immunity as a net encircling your friends and family and protecting them from disease, unvaccinated people would be the holes in the net, opening up gaps for disease to make its way into the population. But, so long as a significant majority of people (83-94%, for measles) in the community is vaccinated, the chances for those holes to connect and the virus to spread remain slim.
That’s what Rhett’s father wants.
He lives in a part of Northern California where an abnormally high number of parents have refused to vaccinate their kids. Their county of Marin has the highest rate of “personal belief exemptions” (a form parents and a doctor must sign to opt-out of vaccinating their children) in the Bay Area and one of the highest in California.
This school year, 6.5% of Marin County children of all ages have the exemption from their parents, a modest drop from last year, since a new law instated in January required parents who file the exemption to have a conversation with their doctor and get their signature before doing so. At Rhett’s elementary school, about 7% of kids are not vaccinated (including those who have the exemption and those who cannot get vaccinated, such as those allergic to a component of the shot), the Times reports.
But in order to prevent unvaccinated children from coming to school, Rhett’s father would have to convince Marin County health officer Matt Willis, who told The Times that such a ruling would be inappropriate since the county hasn’t seen a case of measles in years. (Marin County is near San Francisco in the far north; Orange County, the epicentre of the California outbreak, is near Los Angeles in the far south.)
Measles Isn’t Gone — And It’s Far From Harmless
Measles isn’t a harmless disease — and it spreads easily. For every person it infects, 12-18 more typically get sick. So despite high national vaccination rates of close to 90%, the disease has still managed to spread relatively quickly in some pockets with lower rates, like in California.
“Almost everyone who has not had [the] vaccine will get measles if they are exposed to the measles virus,” the CDC warns.
To give this some perspective, take an analogy from Dan Diamond, the executive editor of The Daily Briefing, a healthcare publication. “If you’re unvaccinated, you’re about 35,000 times more likely to die from measles than you are to win at PowerBall,” Diamond writes in a recent post on Forbes.
Nevertheless, the rates of unvaccinated people, including children and adults, are rising.
In 2014, the Centres for Disease Control and Prevention documented 610 cases of measles spread out across 24 states in the US — the highest case count since 1994. In some parts of California, the state where Rhett and his family live, the vaccine exemption rate for young children is 13% — higher than in Ghana, where it’s 11%, Diamond reports.
As of right now, there are no confirmed or suspected cases of measles anywhere in Marin County. But “if the outbreak progresses and we start seeing more and more cases,” Willis told NPR, then requiring unvaccinated kids to stay at home “is a step we might want to consider.”
NOW WATCH: Briefing videos
Business Insider Emails & Alerts
Site highlights each day to your inbox.