COVID-19 vaccination for 5-to-11-year-olds is finally a go. But even as the emergency-use-authorization process unfolded, so too did arguments over whether kids should (or would soon) be forced into getting shots. School mandates for new vaccines tend to lag behind CDC recommendations by about half a decade, but COVID-19 shots appear to be in the express lane. The Los Angeles Unified School District—the nation’s second-largest—will require students 12 or older to be vaccinated by mid-December if they want to continue attending in-person classes. The entire state of California plans to mandate shots for all of its public- and private-school students as soon as vaccines are fully approved for them, and New York City’s mayor-elect has said that he supports the same idea.
The implementation of any statewide K–12 school mandates may still be a while off, given the expected delay before the FDA gives full approval of shots for kids—for reference, the same process for the adult vaccines took eight months. In the meantime, parents, pediatricians, and public-health officials will be left to ponder the pros and cons. COVID-19 may be an unprecedented disease prompting an unprecedented vaccination effort to match. But how, exactly, does the case for mandating COVID vaccines in schools compare to the one for all the other shot requirements—such as those for polio, chickenpox, and measles—that are already in place throughout the country?
When state regulators are deciding whether to mandate a given vaccine, they generally consider the risks and benefits—just like the FDA and CDC do when deciding whether to green-light a vaccine—but also how those risks and benefits relate to a school environment, says Mary Anne Jackson, an infectious-disease pediatrician at University of Missouri at Kansas City’s Children’s Mercy Hospital. In addition to being safe and effective, a vaccine should be easy to distribute and well accepted among the medical community and the public. Under these conditions, school vaccination mandates can provide “a safety net for vaccine policy,” says Jason Schwartz, a vaccine-policy expert at the Yale School of Public Health. They help bring up immunization rates when other methods of persuasion have failed.
The most important benefit of mandatory COVID vaccination, as far as parents are concerned, would be its potential to prevent death. COVID-19 has, up to this point, caused relatively few deaths in children ages 5 to 11—66 from October 2020 to October 2021. But we routinely vaccinate schoolkids against diseases that were even less deadly before their respective vaccines were available. Chickenpox, for example, killed an average of 16 5-to-9-year-olds a year in the early 1990s; now all 50 states (as well as the District of Columbia) require that elementary schoolers be vaccinated against it. Chickenpox, Jackson told me, used to kill “a certain subset of kids”—mostly those who were immunocompromised. The same is true today of COVID-19.
Besides warding off death, COVID vaccines for kids also promise to prevent and mitigate sickness, the long-term effects of which remain unclear in children and adults alike. In data that Pfizer provided to the CDC, the company’s little-kid dose was 90.9 percent effective at staving off symptomatic infections. (Keep in mind, though, that the vaccine’s effectiveness may change over time, as it has for adults.) This level of protection is comparable to that provided by vaccines mandated for elementary schoolers in all 50 states: polio (99 percent), measles (97 percent), chickenpox (94 percent), and pertussis (84 percent).
It’s also important to consider how likely kids are to contract the disease to begin with. The Delta variant appears to be less transmissible among children than chickenpox, measles, and pertussis, and about as transmissible as polio. But we have very little data on how rapidly the Delta variant spreads among schoolchildren in particular, and how much more rapidly it would do so if precautions such as masks and social distancing were removed from schools.
To sum up the benefits: The kid-size COVID vaccine fights a disease that is about as dangerous as others for which schools regularly require vaccination, and, at least for now, it appears to be about as effective as these other vaccines, while the disease it prevents appears to be slightly less transmissible.
Now for the risks. The main concern with the Pfizer kid vaccine is myocarditis, a condition in which the heart muscle becomes inflamed, leading to symptoms such as chest pain and shortness of breath in children. Non-vaccine-caused myocarditis tends to be rarer in young children than in teens and young adults, and Pfizer’s little-kid trial didn’t result in any recorded cases among its roughly 3,000 vaccine recipients. But among older boys and young men who have received a second dose of an mRNA vaccine, myocarditis has been observed in roughly one in 10,000.
How does this rate compare to rates of the most troubling side effects from school-mandated vaccines? COVID-vaccine-induced myocarditis occurs less often than febrile seizures do after the measles, mumps, and rubella vaccine (about one in 2,500 doses), but more often than a bruising condition called immune thrombocytopenia purpura (one in 30,000). The myocarditis cases are also more common than cases of anaphylaxis after the Hepatitis B vaccine (one in 1.1 million), which is required for elementary schoolers in all but a handful of states.
But the rate of COVID-vaccine-induced myocarditis doesn’t tell us that much on its own. “The question is, how severe is myocarditis?” says Daniel Salmon, who directs the Johns Hopkins Institute for Vaccine Safety. We still don’t really know. According to the CDC, most patients with post-vaccine myocarditis “felt better quickly,” and “can usually return to their normal daily activities after their symptoms improve.” But no one can say yet whether a bout of vaccine-induced myocarditis now would harm someone’s health in a year, or 10 years, or 50. Salmon told me he wouldn’t support a kids’ mandate until researchers are able to rigorously follow kids who get myocarditis for a year or two, and find no related serious health problems.
Waiting a year or two would also give regulators a chance to see how Americans learn to live with SARS-CoV-2 as an endemic virus, which has its own implications for any potential mandates. Lainie Ross, a pediatrician and bioethicist at the University of Chicago, told me that right now, “what makes this disease unique is that everybody is sort of a virgin” to the virus that causes it. If it doesn’t continue to transform into new and more dangerous variants, and if the vaccines (or natural immunity left by previous infections) remain protective against it, then COVID-19 will likely start to resemble measles or chickenpox: It will become a childhood disease, because every living adult will already have been exposed. That makes the case for childhood mandates much easier.
But if, as some experts (and pharmaceutical-company CEOs) have predicted, the virus changes so much that we’ll need to get a new shot once or twice a year, mandates for schoolchildren would suddenly get a lot more complicated. Most schools track routine vaccinations at particular entry points, like enrollment in kindergarten or middle school, says Seema Mohapatra, a visiting law professor at Southern Methodist University, and they have practiced systems for doing so.
Should the COVID vaccine become an annual shot, “that’s a whole different story,” she told me. The paperwork, she said, would be a nightmare.
Consider the flu vaccine. During the 2019–20 season, 112 children ages 5 to 17 died of flu, yet no state mandates annual flu shots for K–12 students. (Massachusetts announced a mandate in August 2020, then dropped it in January after the flu season turned out to be mild.) In contrast, an average of three children and teens a year died of Hepatitis A in the five years before the two-doses-and-that’s-it vaccine for that disease was licensed. Yet Hepatitis A vaccines are mandatory in grade schools in one-third of states. True, the Hepatitis A vaccine is significantly more effective than the annual flu shot, but the flu arguably presents a much more formidable danger to kids.
The miraculous speed at which the COVID vaccines were developed has only made these questions harder to work out. By the time the first emergency use authorization was issued for Pfizer’s adult shots last year, humankind had had only about 13 months of experience with the new coronavirus. The first American polio epidemic occurred decades before Jonas Salk began work on his famous vaccine; measles was around for centuries before an effective inoculation was discovered. If we’d had that kind of time with COVID-19 before vaccines were introduced, a lot more kids would probably have gotten sick or died from the disease, but we’d also know a lot more about how rapidly the virus mutates over time, the exact degree to which kids spread and get infected by it, and the rate at which it causes chronic symptoms.
Likewise, any scraps of information that can be gathered in the next few months will be of use in deciding whether to mandate the vaccine for kids. The approaches taken by mayors, governors, and regulators so far suggest that most intend to wait until the FDA grants its full approval for the shots. By then, we should have some more to go on.