LOS ANGELES — For almost two years, COVID-19 vaccine holdouts have been the objects of earnest pleading and financial inducements, of social-media shaming and truth campaigns. They’ve missed weddings, birthday celebrations and recitals, and even forfeited high-stakes athletic competitions. Until last month, they were barred from entering the United States and more than 100 other countries.
Now the unvaccinated are suddenly back in the mix. They’re dining in restaurants, rocking out at music festivals and filling the stands at sporting venues. They mingle freely in places where they used to be shunned for fear they’d seed superspreader events.
It’s as if they’re no longer hazardous to the rest of us. Or are they?
“Clearly, the unvaccinated are a threat to themselves,” said Dr. Jeffrey Shaman, an infectious disease specialist at Columbia University. As recently as August, their risk of dying of COVID-19 was six times higher than for people who were fully vaccinated and eight times higher than for people who were vaccinated and boosted, according to the Centers for Disease Control and Prevention.
But, Shaman acknowledged, “the danger to the rest of us is a more debatable issue.”
When public officials imposed vaccine mandates, the unvaccinated certainly appeared to pose demonstrable dangers to their communities.
State and local leaders sought not only to suppress spread of the virus, but also to prevent their health care systems from being overwhelmed, degrading care for all. The unvaccinated made those goals harder to achieve since they were more likely to become infected and, when they did, to require hospitalization.
U.S. officials had long hoped to vaccinate the American public into a state of “herd immunity,” in which so few people would be vulnerable to the virus that the outbreak would simply sputter out. That objective assumed a uniformly high uptake of vaccine across the nation. It also assumed a vaccine that protected against reinfection, and did so durably.
But none of that came to pass. About 30% of Americans have yet to complete their initial series of COVID-19 shots, including the 20% who haven’t rolled up their sleeves even once. Meanwhile, the virus continues to evolve in ways that erode vaccines’ protection, making “breakthrough infections” increasingly common.
The longer the pandemic drags on, the more complicated things get.
For one thing, whether those who remain unvaccinated are still driving coronavirus spread hinges partly on the status of the U.S. population’s immunity. Almost three years into the pandemic, that is a hard map to draw — both because the public’s immunity comes from different sources, and because it waxes and wanes.
More than 200 million adults and nearly 25 million children ages 5 and up have completed a primary series of COVID-19 vaccine. However, against the omicron variant, just being “fully vaccinated” confers little more than a whiff of protection against infection and illness.
For the 49% of “fully vaccinated” Americans who’ve had at least one booster dose, infection remains a possibility, but the prospects of becoming seriously ill or dying of COVID-19 are sharply reduced.
And then there’s the “natural immunity” gained from a coronavirus infection. By February 2022, after the first wave of omicron infections swept across the U.S., 58% of Americans were believed to have been infected at some point in the pandemic, leaving them with some modest level of protection. The ranks of the previously infected have surely increased since then thanks to the second omicron surge during the late spring and summer.
An unknown number of Americans have “hybrid immunity” from both an infection and vaccine. Researchers believe that catching the coronavirus after vaccination (though not so much the other way around) may provide enhanced protection against severe illness and death. But whether that is the case — and how much — can vary based on how long ago an infection took place and the particular variant that caused it.
