When the pandemic first began rolling through the United States, getting tested for COVID-19 was nearly impossible, something reserved for those who were extremely ill. In New York City, the health department told physicians in late March to only test patients that needed to be hospitalized. The United States wasn’t equipped to perform the sort of testing needed to identify COVID-19 at the rate suddenly required.
Several months ago, after New York City’s previously high infection rate lessened and the initial curve was moderately flattened, the city’s health department changed its tune: “All New Yorkers should get tested now, whether or not you have symptoms or are at increased risk.” Getting a COVID-19 test in New York, and in several other states that have been more successful at curbing their infection rates, is now as simple as booking an STI panel. And some people are treating it just that way, getting tested at regular intervals—regardless of symptoms or known exposure—in order to be aware of their COVID status.
But is that wise? After watching public health officials lament the lack of testing—something that had deadly consequences for thousands of people—all spring, it feels a little strange to hear people now urge for the normalization of routine COVID testing. Is that possible? Are we merely running the risk of sucking the well dry, and winding up where we were back in April? What is the most responsible way to go about testing, seven months into a still-going pandemic?
From a public health perspective, more testing is good and necessary, and will be a facet of an eventual return to normalcy. “Eventually, we’re going to get to a point where everybody gets tested all the time, hopefully at home, so that they can know whether they’re contagious or not,” Amesh Adalja, an infectious disease scholar at Johns Hopkins who has been treating COVID patients for months, told VICE. “But I don’t think we’re quite there yet.”
Adalja, an essential worker who’s been taking care of COVID patients throughout the pandemic, said he has never been tested for COVID-19, a fact “people are very surprised” to hear. But he’s never been symptomatic, and so he’s never needed a diagnostic test. He clarified that right now, with testing limitations being what they are, the priority should still be on diagnostic testing for people who have symptoms of COVID-19 or have been in close contact with a known case. He further clarified that screening tests—or asymptomatic, seemingly healthy people getting tested in order to know their status—is not yet something we have the infrastructure for.
“There’s just major shortages still, we don’t have enough reagents, the turnaround times are very long for getting tests back,” Adalja said. “We want to prioritize symptomatic people. If you have symptoms, you should go to the front of the line. We’re in a resource-constrained situation; there just isn’t enough testing availability for every person to get tested.”
Even as reverse-transcription polymerase chain reaction tests, or PCR tests, which have been at the center of our COVID response so far, are now readily available in New York City, other states and regions continue to struggle with turnaround times. Earlier this summer, just as New York was seemingly swimming in testing capacity, Houston—another emerging outbreak epicenter—was drowning. Tests were getting lost and taking upwards of two weeks to come back (at which point they’re effectively useless). Whether that was because too many people were afraid and getting screened, or if suddenly everyone had reason to believe they may be infected with COVID-19, is impossible to know. Harris County, where Houston is located, required at the time—and still requires—those wishing to get tested to fill out a questionnaire that assesses their need for a test.
Adalja explained these types of questionnaires are likely designed to filter and prioritize need—who needs to be tested quickly because they’re symptomatic, and who wants to be screened to quell their anxiety, or to go see a group of friends.
The testing supply-chain issues we experienced in the first months of the pandemic haven’t totally resolved. “A lot of tests require isolation of the RNA, and it turned out there weren’t enough kits around because we didn’t used to isolate so much RNA,” Marta Gaglia, a virologist at Tufts University, told VICE. “There were real supply-chain issues. It’s literally like, we are not making enough of the things we need to do the test. Because we never needed them on this kind of scale.”
Different states, regions, cities, schools, and companies are using different tests, and leaning on different supply chains, Gaglia said. Some places—like New York City, to keep using that example—currently have stable supply chains and some semblance of testing infrastructure, which is why the city health department can encourage regular testing for all New Yorkers, at least for now.
But in Texas and Florida, where case numbers remain high, governors have consistently downplayed the severity of the pandemic in favor of reopening the economy, privately owned testing sites have been known to pop up in abandoned strip centers, and statewide testing numbers are inaccurately reported to make conditions look better than they really are, questionnaires are still used to determine who needs testing, and who doesn’t.
That may eventually change, Gaglia said. From a public health perspective, regularly screening asymptomatic people is good and necessary. “The idea is to be able to pick up asymptomatic cases, essentially; the people who don’t show symptoms but might still be contagious,” she said. “Or find people who are sick before they actually have symptoms, which is thought to be a big source of transmission. That’s really the goal of screening, is to try and more quickly identify potential outbreaks, and do the contact tracing.”
But screening is a public health pursuit, not a choice every individual can make for themselves. Choosing to get screened once a month or so is not likely to make a huge difference in preventing any major outbreaks, unless you’re a person who is routinely around a lot/large groups of people. Screening is effective when many people are doing it, and there’s some degree of top-level organization involved.
“I don’t know if a single person should be encouraged to go for repeated testing, unless they’re in a lot of situations where they’re in a lot of contact, then maybe it makes sense for them,” Gaglia said. “This is something that I think should be organized on some level, which is what employers and universities have started to do, for example. Universities still had outbreaks, but they did modeling to try and figure out how many times to screen, and which populations to screen more often.”
Screening regularly—whether that’s at home, like Adalja said, or every few weeks at your reopened office or school—is going to be a component of a return to normalcy, whenever that happens. It may look like simple, at-home tests (which we don’t yet have, but are one of several possibilities) or regular testing at a reopened office or school. But we’re not there yet. “The issue is that, if there are a lot of cases, screening is not so useful,” Gaglia said.
Logistically, it would be incredibly difficult to contact trace if everyone in the United States was somehow able to begin routine screening tomorrow; the number of active cases that would be swept up would be extremely high, and everyone is still meant to be social distancing and quarantining, anyway. We’ve already seen how that can break down at reopened college campuses: The University of South Carolina encouraged students to get tested when they returned to campus, regardless of symptoms, and then found itself with more active cases of COVID-19 than any other campus in the country. The school, drowning in positive cases, quickly rolled back its testing capacity, reducing the number of tests it provided daily. Too many students turned out to be sick. Contact tracing, even on the controlled environment of a college campus, was impossible to carry out.
To address the supply-chain issue associated with PCR tests, some public health experts and epidemiologists are currently enthusiastic about the new antigen tests, which detect viral protein in a saliva sample, rather than by isolating RNA. Antigen tests have weaknesses compared to PCR tests: they aren’t as good at detecting low-levels of infection, for instance, and have a higher likelihood for delivering false results. But they’re otherwise cheap, deliver results in 15 minutes (as opposed to the sometimes days-long cycles of PCR tests, which render them nearly useless in a lot of scenarios), and don’t come with as many supply-chain issues as PCR tests.
Because of these attributes, Michael Mina, a professor of epidemiology at Harvard, is perhaps their biggest proponent; Mina believes wide scale antigen testing could be the way the United States becomes capable of testing people at the rate necessary to more safely return to somewhat normal.
As Gaglia mentioned, even in a future where everyone can be doing antigen tests any time they go out in public, none of the individual tools we have for combatting the pandemic can work on their own. “Even if you did screening and surveillance, I don’t think that would remove the need for things like social distancing and masking,” Gaglia said. “It would just be one way to make everything a little less risky.”
A simple graphic I saw recently illustrates this better than anything I’ve read so far. It’s called the Swiss Cheese Model: A bunch of slices of swiss cheese, with their little swiss-cheese holes lined up randomly, stacked together, each one representing a different tactic we have for preventing COVID-19. If you stack a bunch of those cheese slices together, almost none of the holes align and virus doesn’t get through. Screening tests will eventually be one of those cheese slices. But only if it’s supported by availability and an organized operation, and isn’t left up to individual choice, which, as we’ve seen so far, is a failure of government and institution.