President Joe Biden’s new vaccine mandate for large businesses is a strange one, in that it does not actually make vaccines mandatory for the roughly 80 million Americans it’s aimed at. Tucked plainly into the rule is a singular and obvious opt-out: Unlike federal employees and contractors, those in the private sector can test for the coronavirus on an at-least-weekly basis, a no-jab alternative that makes the White House’s decision quite a bit gentler than it could have been. “It’s a stick, but it’s sort of a soft stick,” Julia Raifman, a health-policy researcher at Boston University, told me.
The two-pronged approach is certainly more flexible, and perhaps more politically palatable, than pushing shots alone. Recent polling suggests that a majority of Americans are on board with mandates, at least when they’re doled out as a double scoop. “People like choices,” Syra Madad, an infectious-disease epidemiologist at Harvard and for the New York City Health System, told me. That’s long been true for public-health carrots as well: In places such as Israel, the European Union, and parts of Canada, negative test results are among the “passport” options that can green-light residents for entry into restaurants, bars, gyms, clubs, and travel hubs; a smattering of similar policies have been in place at certain American businesses for months.
The details of Biden’s new mandate are still being worked out by the Occupational Safety and Health Administration, and the logistics will differ among states and individual companies. But it’s one of the most prominent iterations of the test-vax binary to date—and potentially one of the most troubling. The United States isn’t set up to handle a sharp rise in diagnostic demand, should a big fraction of affected workers go the testing route. What’s more, including the testing clause at all “does undermine, to some degree, the scientific and public-health purpose of the mandate,” Tom Bollyky, the director of the global-health program at the Council on Foreign Relations, told me. Vaccines and testing are simply not interchangeable. And the false equivalence that the mandate implies could push us to, once again, play either-or with pandemic mitigation measures, when the best move has always been to use them in combination.
Vaccines and tests were designed for explicitly different purposes. COVID-19 shots are proactive, forward-looking measures: They offer viral anatomy lessons to immune cells in advance of an encounter, schooling them on how to fend off a pathogen without actually forcing them to fight it. Infections of all severities are uncommon among the vaccinated. When they do occur, they’re milder, briefer, and less likely to spread to others, and they almost never end in hospitalization or death. Vaccines are an investment in the long term, a sustainable preventive against disease; they bolster the body’s defenses, upping a person’s chances of coming away from a viral encounter unscathed.
Tests, while powerful in their own right, don’t offer any of those perks. They’re measuring tools that home in on snippets of viral genetic material or hunks of viral proteins in someone’s airway, and can only identify infections that have already begun. That makes them reactive by default, Saskia Popescu, an infection-prevention expert at George Mason University, told me. Tests offer one result at a time, a snapshot—at the moment of sampling, you had a detectable smidge of virus in your nose or mouth, or you didn’t—with zero bearing on what’s to come. “You incur no protection from a test,” Susan Butler-Wu, a clinical microbiologist at the University of Southern California’s Keck School of Medicine, told me. “With a vaccine, you are protected, and you are protecting.”
The Biden administration, of course, is not billing tests as functional vaccines. But as written into the mandate, tests are still being cast in an understudy role that they were never meant to play. “It’s an unacceptable alternative,” Jennifer Nuzzo, an epidemiologist and senior scholar at the Johns Hopkins Center for Health Security, told me. Tests can’t be swapped in for vaccines for the same reasons a smoke detector can’t sub in for fireproofing, a car speedometer can’t replace a seat belt, and a weather report can’t take the place of an umbrella. Noticing the problem isn’t the same as blocking it. (The White House did not respond to repeated requests for comment.)
Realistically, the mandate probably needed a fail-safe like this to survive the political climate. “Policy makers have to operate in the realm of what’s possible,” which doesn’t always match up with what’s scientifically ideal, Bollyky said. Having a testing clause, he added, will help buffer the policy against legal challenges—which are already being lobbed its way—that might have otherwise driven it entirely into the ground. A squishy mandate is probably better than a doomed one.
And of the available options, testing was, perhaps, the best alternative on a very short list—something tangible, implementable, with FDA-okayed products already in place. Plus, regular screens can truly make workplace settings safer, well in line with the mandate’s primary objective. Every infection that’s caught is one that can potentially be managed, treated if necessary, and contained before it spreads further, if the positive result is acted upon. Months of studies, many of them run at universities with large laboratories and funding pools that the average private business might not have access to, have shown that repeated testing of students, staff, and faculty has smoothed the transition back to in-person learning, and helped catch and corral outbreaks.
But a glut of data has also proved that testing, even when mandated, can’t halt infections alone; the strategy’s been most successful when paired with masking, physical distancing, and, more recently, vaccines. Tests aren’t perfect. Some cases will inevitably slip by unnoticed, while some virus-free individuals will be mislabeled as infected. The reach of tests also hinges heavily on human behavior: People actually have to “take action to be protected,” Nuzzo said, isolating themselves after receiving a positive result and reporting their status, formally or informally, so that they can alert others who were potentially exposed. Vaccines juice up immune systems so that viral defense becomes a reflex; tests just flag the issue, then wait for users to make the next move.
Dan Larremore, a mathematical modeler at the University of Colorado at Boulder, who’s crunched numbers on the contagion-curbing effects of frequent testing, told me that tests can absolutely “reduce cases by a substantial amount.” But given a choice, “transmission is reduced more effectively and more cost effectively by vaccination.”
The bare minimum test frequency needed to meet the mandate standard—once a week—also isn’t terribly compatible with good mitigation. People tend to become contagious within about four to six days of getting infected, likely a shade sooner with the speedster Delta variant. And a big fraction of transmission happens before the infected show symptoms, if they ever do. A weekly screen could leapfrog that entire window and end up being “too little, too late,” Valerie Fitzhugh, a pathologist at Rutgers University, told me. (Even the EU health passports that accept negative test results expire after just two to three days.)
The situation could get even murkier if employees need to wait several days for their results, as is often the case with test samples that must be routed through labs. Rapid tests could circumvent that delay, but they’re not very good at zeroing in on low-level infections, and have been shown to operate best, as Larremore and others have found, when used as near-daily screens—a quantity patch for their quality flaws.
Employers could opt for testing more often than once a week to bridge some of these gaps. But frequently testing multiple employees stands to bleed time from the workday, incur heavy financial costs—which could potentially fall on the company, its employees, or both—and stress the nation’s already insufficient diagnostic supply. Demand for testing has skyrocketed since the start of the summer, thanks to Delta’s ongoing crush. Meanwhile, many of the community testing sites that closed in the winter or spring never reopened; at-home tests, now available over the counter, have grown difficult to find in stores and online.
After grappling with nearly two years of SARS-CoV-2 testing, Butler-Wu, who runs a clinical laboratory that processes hospital samples, worries that a massive influx of workplace testing will deplete resources that could otherwise be used to diagnose very sick patients, especially as the nation barrels into the winter months, when many pathogens thrive. “How are people with symptoms going to get tested?” she said. Laboratory workers, she noted, have been stretched to the breaking point since the pandemic’s start. “There is not an infinite capacity to do this.”
The Biden administration has made moves to increase the availability of rapid tests and lower their price points. But the experts I spoke with were skeptical that the supply surge would happen in time, or at a large enough scale. (At this point, it’s still unclear what types of tests will qualify as valid under the mandate, whether they’ll need to be done on-site, and whether their results will need to be reported to public-health officials.)
There’s some hope, Nuzzo said, that the testing slice of the equation will be such a headache for everyone involved that vaccination will look more appealing in comparison and become the default. But even that scenario cloaks what would be the actual ideal: wielding vaccines and tests in combination, alongside masks and many of the other measures we’ve been talking about for months. Immunized people pose a lower transmission risk to others, but not zero. “If your goal is to minimize transmission in the workplace, you want to do both,” Nuzzo said.
Still, if the comparison has to be made, vaccines “will always come out on top,” Madad, the New York epidemiologist, said. Putting them on the same tier as other measures, and blurring the differences among them, threatens to obscure our best shot at ending the pandemic. This is why, perhaps, we’re calling the not-vaccine mandate a vaccine mandate. It’s a wishful nickname, one that highlights, rather than cloaks, just how powerful immunizations can be when all of us buy in.