In fall 2019, before anyone had ever heard of COVID-19, California legislators were trying to pass a bill aimed at increasing childhood vaccination. Five years previously, someone at Disneyland had set off a measles outbreak that infected more than 100 people, mostly unvaccinated, in the state — as well as in six other states, Canada and Mexico. The incident galvanized legislators and led to a series of laws aimed at curtailing the religious and philosophical exemptions that allowed parents to avoid getting their kids vaccinated before sending them to school. Take the exemptions away, the thinking went, and vaccine rates would rise. But the level of vitriol that enters politics when you try to mandate vaccines can be … intense.
“The California Senate had to be evacuated because someone took — and this is more detail than you want — a cup full of menstrual blood and hurled it onto the Senate floor,” Alison Buttenheim, a professor of nursing and health policy at the University of Pennsylvania, told me.
Today, things are similarly tense. COVID-19 vaccination requirements are taking effect across the country. Universities are requiring students to get vaccinated. Businesses are mandating vaccines for employees and customers. States, cities and the U.S. military have made COVID-19 vaccination a must for public employees. But, as in California, the pushback has been fierce, with protests, fake vaccine cards and outright bans on the mandates in some states.
Simply enacting a law or regulation mandating vaccines isn’t enough. California ended up spending years cleaning up loopholes that parents used to get out of vaccinating their kids. The fact that the California legislature was still tinkering with the state’s vaccination laws in 2019 says a lot. To this day, the state medical board is dealing with physicians who were willing to write thousands of bogus medical exemptions.
Mandates work. As the laws changed, vaccination rates among California kindergarteners did go up. But ideological values, deeply personal fears and (increasingly) political polarization all mean that a vaccine mandate isn’t just a switch you flip on and walk away from. Instead, a mandate is a finicky machine that has to be maintained, lest it fall apart.
School entrance mandates are probably the single most effective thing we’ve done to achieve high vaccination rates in the United States, said James Colgrove, a professor of sociomedical sciences at Columbia University. “Can you achieve it through voluntary means? No. Not really,” he told me.
Mandates have focused on kids both because they are particularly at risk of severe illness and because schools are such a perfect incubator for transmission. Pack a bunch of people with no naturally acquired immunity into one building five days a week, add a child’s complete lack of boundaries and you’ve got disease soup.
But the country has long waxed and waned on whether to require kids to get vaccinated. School vaccine requirements have been with us a long time — nearly as long as public schooling itself. Smallpox vaccination — the only vaccine that existed early in the history of public education — was required for entry into Boston public schools in 1827. But for much of American history, mandates were inconsistently applied across geography and tended to come and go over time. For example, Washington and Wisconsin ended school vaccination requirements in 1919 and 1920, respectively, and during the 1920s, the Utah and North Dakota legislatures passed laws forbidding compulsory vaccination.
But mandates became more of a mainstay in the late 20th century, when a series of school-based measles outbreaks swept the nation in the 1970s — and it quickly became clear that vaccines could help. In Texarkana, a city split by the Texas-Arkansas border, the Arkansas side had a vaccine mandate and fared far better than the Texas side, which had no mandate. By 1980, every state had some kind of compulsory vaccination for school-age children. Annual cases of measles dropped from tens of thousands in the 1970s to fewer than 2,000 by 1983. During the 20th century, measles infected an average of more than 500,000 Americans each year. In 2005, after decades of school vaccine mandates and vaccination rates higher than 90 percent, it infected 66 people. Vaccines reduced the spread of disease, and making the vaccines mandatory all but eliminated it.
It’s evidence like this that gives public health experts solid reason to think requiring a COVID-19 vaccine — whether in workplaces, for school attendance or to go to places like restaurants — would boost vaccination rates and reduce illness in a way that purely voluntary vaccination campaigns just can’t.
But it’s not as easy as snapping your fingers and having everything work out. To get them right, vaccine mandates require compromise, tinkering and a lot of legal and political follow-up. COVID-19 mandates will almost certainly demand the same.
Hanging over everything is the tradeoff between getting more people vaccinated and shutting out those who aren’t vaccinated. Douglas Diekema, the director of education for the Treuman Katz Center for Pediatric Bioethics at Seattle Children’s Hospital, noted that anytime a government institutes a school-based mandate, they’re balancing two public goods: preventing disease and getting kids educated. “I think you need a good reason … to take that benefit away from people who won’t get vaccinated,” he said.
COVID-19 vaccination requirements are bound to run into similar priority struggles. We, as a society, want more people vaccinated — we also want people to be employed and be able to go to college. And unlike the diseases that childhood vaccines have strongly curtailed, COVID-19 is an active pandemic. The choice isn’t just about “prevention” versus “access to societal services.” You have to factor in the health and lives of other people too.
Not everyone will make the same choices about how to balance access with safety. States have significantly different requirements about how many vaccinations are required to go to school, and whether they’re really required. Some vaccines are required for school entry in every state — measles, polio, diphtheria — because they have extremely high efficacy rates and are related to diseases that spread through normal daily contact with other kids in schools. But only six states — plus New York City — require flu vaccines, which have lower efficacy. Only three states require vaccination for human papilloma virus — a disease that’s spread by sexual contact, and which has been heavily politicized by groups that framed it as giving preteens and teenagers adult approval to go have sex.
It’s likely COVID-19 vaccine requirements will remain a patchwork as well, said several experts I spoke with. Politicization and breakthrough cases are likely to mean the COVID-19 vaccine has more in common with the ones for HPV and flu than it does with the one for measles.
Even once you decide on rules, you have to decide on how staunchly to enforce them. In schools, all states allow medical exemptions because some children have immune disorders or specific allergies to vaccine ingredients. Forty-four states allow parents to exempt their children from vaccines because of religious beliefs, a product of heavy lobbying efforts by Christian Scientists during the 1970s. Other exemptions for vaguer “philosophical beliefs” — which 18 states now offer — evolved over time as a response to legal concerns about states favoring religion. Colgrove referred to all these exemptions as a “safety valve” — a way of accommodating the very small percentage of people who will never accept vaccination, without creating political standoffs or forcing children out of school.
The challenge for COVID-19 vaccines, as for childhood vaccines, will be in how to offer exemptions without making exemptions too easy to get. Several of the five researchers I spoke to told me that over the past decade a few states have dealt with the problem of childhood vaccination by tightening restrictions and providing better access to vaccines — making it logistically easier to get immunized than to get out of it.
Still, there’s the question of what to do when some flout the rules. “This is not stuff that’s fun for anybody to enforce,” said Buttenheim. “In California, with public schools at least, the schools have a huge disincentive to exclude kids, because they don’t get paid. So excluding a kid for vaccination status loses you money as a school.” Nationwide, it’s not uncommon for schools to give parents time to catch up on mandated vaccines without kicking kids out — and sometimes once parents are granted extra time, schools don’t have the staffing resources to follow up, said Peter Hotez, a professor of pediatrics and molecular virology at the Baylor College of Medicine.
Creating a vaccine mandate — and enforcing it — is almost certainly going to require governments and institutions to come up with ways of dealing with loopholes and fraud. After the Disneyland outbreak in California, the state eliminated all nonmedical exemptions, becoming one of six states in total. But the change didn’t mean a straight line to higher vaccination rates.
“There were suddenly a whole lot more medical exemptions,” Buttenheim told me. Medical exemptions increased by 250 percent over the next two years — with many of the exemptions being signed by a handful of doctors. Between 2016 and 2018, the number of unvaccinated kindergarteners being homeschooled quadrupled. Making the mandate actually work has turned out to be a game of whack-a-mole, with legislators passing laws that specify which medical issues count as vaccine exemptions and establishing a surveillance system that approves exemptions and flags doctors for investigation if they’re handing out a lot of get-out-of-vaccine-free cards. While Buttenheim’s research suggests this has reduced and will continue to reduce the overall share of unvaccinated children in California, it takes a lot of work and resources to increase vaccination rates by 1 percent, or even less.
The push for COVID-19 mandates could also have repercussions for other childhood vaccinations. Already, the Tennessee legislature has responded to COVID-19 vaccination by pressuring the state department of health to stop promoting any vaccine to minors — including school-based vaccine clinics, something that research has shown is crucial for getting vaccines to kids whose parents might be comfortable with vaccines but who have budgets and work schedules or a lack of medical access that pushes vaccination down the family priority list. That’s on top of social disruption due to the pandemic itself, which has already reduced childhood vaccine uptake nationwide.
The bottom line, according to the researchers I spoke with, is that vaccine mandates are a really powerful public health tool. They’re effective, the childhood vaccine mandates have been widely supported, and they’ve been consistently upheld by the Supreme Court. But that doesn’t mean they’re easy to implement. As Buttenheim put it: “It’s messy business.”