FALSE SENSE OF SECURITY

I took an at-home Covid-19 test. I can see my friends now, right?

The other options for a birthday party right now.
The other options for a birthday party right now.
Image: Reuters/Emily Elconin

Theoretically, if everyone in a group tests negative for SARS-CoV-2, they could all safely meet up indoors with no masks or physical distancing. Yet with ongoing shortages of federal and state-provided testing in some areas, plus significant lag times to get results, it’s been hard for Americans to successfully carry out these plans.

Enter capitalism. The US Food and Drug Administration has granted emergency use authorization to several at-home Covid-19 tests developed by companies like LabCorp, Quest, and Everlywell. These tests offer nearly everyone the ability to collect a nasal swab sample from the convenience of their couch, and they’ve become a popular option for those who want to try to regain a semblance of normalcy. But it’s important to remember that negative test result can’t eliminate transmission risk entirely. Together with other risk-mitigation strategies, they simply make some lower risk hangouts possible.

How do at-home Covid-19 tests work?

As healthcare efficiencies go, at-home tests are hard to beat. Customers take a quick survey to gauge whether they may have Covid-19, even if they’re asymptomatic. If approved, they receive priority-shipped collection containers for nasal swabs, cold packs, and expedited return shipping labels. Collecting a nasal sample involves a cotton swab at the base of the nostril, and voila! Ship it back and get results in just a few days.

LabCorp is one of the two major Covid-19 testing companies used by doctors’ offices and other testing sites; Pixel is its consumer-facing brand. Tests by Pixel use the same polymerase chain reaction to look for SARS-CoV-2 genetic material as the test someone would receive in a hospital; essentially, the packaging is flashier and more consumer-friendly.

LabCorp created Pixel in November 2018, and allowed users to order at-home tests for things like vitamin deficiencies and basic assessments of kidney and liver functions. In early April, Pixel launched a Covid-19 test that was intended at first for only symptomatic healthcare professionals and other first responders. By May, the company had expanded its criteria: Anyone who believed they had been exposed—meaning they were in a large crowd where maintaining distancing wasn’t possible, or they had been around someone who was sick—could get a test.

Other companies have since jumped in on the action, including Quest, another major testing company, Everlywell, and Let’s Get Checked. Their tests cost between $100 and $130, and some, like LabCorp’s, can be covered by federal and private insurance. Some of that cost goes into testing and shipping, and a small portion goes to paying for an independent physician to review the consumer’s eligibility. Each test has a results turnaround time of a few days, making them seem perfect to head off any risks at planned gatherings. But are they enough?

Can traveling to visit family or friends increase my chances of getting and spreading COVID-19?

Unfortunately, yes—even if you all get tested ahead of time.

“[Covid-19 tests are] only positive during a very narrow window,” says Michael Hochman, a physician at the Keck School of Medicine at the University of Southern California. SARS-CoV-2 takes a median of five days to make its presence known in the body; sometimes, it can take up to two weeks. If a person were to take a Covid-19 test too soon after being exposed, they’d get a false negative.

A review from researchers at Johns Hopkins University found that over the four days of infection before a person typically starts showing symptoms (on day five), the probability of a false negative was 100% on day one and 67% on day four. Three days after the onset of symptoms, there was still a 20% chance they’d be incorrectly told they didn’t have the virus.

If someone showing no symptoms gets a Covid-19 test and it’s negative, “that’s not particularly reassuring,” says Hochman. “We should all the time act under the assumption that we are an asymptomatic carrier and that everyone around us is, too.”

That doesn’t mean you should stay home alone. Rather, it’s all about finding ways to mitigate your risk—and the first step there is realizing that a truly zero-risk situation doesn’t exist.

First, be smart about the kinds of activities you engage in. Spending time outdoors is ideal; hanging out indoors with masks on for short periods of time is also lower risk, and probably safe to do. Ditto sharing a car with the windows down. As always, you should avoid seeing someone who is sick indoors, especially without a mask.

Finally, consider who is in your group, and who you all may be seeing afterward. If you or those you’re planning to travel with are at risk for developing a severe case of Covid-19, consider rethinking your plans. It would also be wise to abide by the 14-day quarantine once you’re back from wherever you go. And above all, it’s still important to make sure everyone in the group is comfortable taking on those risks, and understands them.

Correction (Sept. 21): A previous version of the story stated that Everlywell offers genetic tests; they offer tests assessing heart health, thyroid function, liver function, allergens, and STI tests.