11 COVID Questions People Still Have, Answered

What we know about Paxlovid, how to handle a positive test, and when to get a booster

A photograph of someone swabbing their nose
Allen J. Schaben / Getty

For almost two years, answering readers’ COVID-19 questions was part of my job as the writer of this magazine’s daily newsletter. We discussed what activities were safe in the early days of the pandemic, when and where to slap on a mask, what to make of new coronavirus variants, and more. So when my partner came down with a fever one night this summer, I thought it was my time to shine.

Things didn’t quite go that way. Even having spent a good chunk of time trying to think through every practical implication of this virus, I still had moments where I thought, Huh, you know, I actually don’t know what that means. This is a confusing virus, and just about everyone who gets it—or who lives with someone who gets it—will find themselves a little lost as the experience unfolds.

Of course, we’ve come so far in our understanding. (One of the first questions we ever addressed was in March 2020, about touching your face.) But even after all this time, a few common questions are still lingering. With the help of some experts and my colleagues, I’ve tried to address 11 of those below. (If you’ve got a COVID problem that you still haven’t been able to sort out, feel free to email me.)

1. Should you take Paxlovid if offered?

We know that Paxlovid is particularly good at one thing: decreasing the likelihood that a high-risk person needs to be hospitalized. It does, however, come with a chance of uncomfortable side effects, such as a metallic taste in one’s mouth or a rebound infection.

Experts told me that whether you should take Paxlovid depends on how at-risk you are for severe disease (in other words, how likely you are to need to go to the hospital). People who are older, immunocompromised, unvaccinated, or overweight are at higher risk.

Robert Wachter, the chair of the department of medicine at UC San Francisco, considers himself a borderline case. “I’m 64. I’ve had four shots. And if I got COVID, I probably would take it,” he told me. “If I was 55, I probably wouldn’t.”

2. If someone in your household is sick with COVID, should you bother trying to isolate them?

Yes! As the writer Yasmin Tayag reported for The Atlantic last month, someone in your house coming down with COVID does not mean that the rest of you are already doomed. In fact, the chance of getting the virus from someone you live with is actually more like 50–50, and that’s after the whole sickness runs its course. So if someone in your house comes down with COVID, there’s a good chance that you don’t have it yet, and isolating them can prevent spread.

While in isolation mode, your household might consider opening windows for ventilation, using portable HEPA filters, and, if you need to be in the same space as a sick loved one, wearing a high-quality mask.

Of course, isolation is not always feasible depending on where you live and who is sick. As Tara Kirk Sell, an associate professor at the Johns Hopkins Bloomberg School of Public Health, told me over email: “If it’s your 5-year-old, then let’s be honest, that’s impossible.” Also, many people’s homes and apartments simply do not have space for people to truly separate.

One exception is if you yourself have had COVID within the past month or so: In that case, you likely had the BA.5 variant, and your loved one likely has BA.5 as well, Peter Chin-Hong, a professor of medicine at UCSF, told me. Because people are thought to be unlikely to get BA.5 twice in quick succession, Chin-Hong said, “you should just enjoy each other’s company and Netflix and chill or whatever you want to do.” Other experts told me that, though the risk of reinfection may be low in these circumstances, it’s not zero.

“The closer you are to your experience with COVID, the more protected you are from subsequent infection, but everyone is different and I wouldn’t count on total immunity,” Sell told me. She said you can lower the chances of an infection by masking up, ventilating, or just limiting the number of exposures.

3. If you had a big exposure recently—say, you weren’t able to isolate from a relative who definitely had COVID—should you also consider staying home? Do you need to keep kids home from school if a parent or sibling has COVID?

The CDC does not currently recommend quarantining after an exposure. It does, however, ask (1) that those exposed to the virus put on a high-quality mask (like an N95) when indoors and around others and (2) that they be extra careful around high-risk people for a full 10 days. Those exposed should also (3) take a test at least five days after the exposure, per the guidelines.

Experts suggested a few additional precautions on top of the CDC recommendations. Wachter told me that he personally would test himself every day. Paul Sax, the clinical director of the infectious-diseases division at Brigham and Women’s Hospital, recommends that those exposed stay put if they develop symptoms, even if their home test is negative. Most conservatively, Pamela B. Davis, a professor at the Case Western Reserve University’s school of medicine, wrote over email that even those who are asymptomatic and negative might consider staying home for a few days.

Sell and her husband both got COVID earlier this year, and were able to mostly isolate themselves from their kids. (“I just made food and put it out for them—they are 6 and 8—and they played a lot of video games,” she wrote.) Because they were able to take precautions, they felt comfortable testing their vaccinated kids and sending them off to school.

4. Do at-home rapid tests work with Omicron?

Yes. “The things that make Omicron Omicron are in a different part of the virus than where the tests are probing,” Gigi Gronvall, an associate professor at the Johns Hopkins Bloomberg School of Public Health, told me.

However, tests need a certain amount of virus to detect the infection. Your body may be more sensitive than an at-home test at this point: Because your immune system is likely now familiar with its COVID foe (having met it through either vaccination or infection or both), it may recognize the virus before your test turns positive, Gronvall explained. This is why people develop symptoms while they’re still testing negative, only to later officially come down with COVID. In August, the FDA recommended repeat testing to lower the risk of a false negative.

When it comes to testing in general, CDC guidelines allow Americans to use either an at-home test or a PCR—with one exception. If you’ve tested positive for COVID within the past three months and you have symptoms anew, you should use a rapid test: A PCR is so sensitive that you may continue to test positive from your previous infection for up to 90 days. (This, too, has an exception. If you had COVID within the past month and are feeling just fine, don’t bother to swab at all: The CDC does not recommend testing within 30 days of a previous infection if you don’t have symptoms.)

5. When can you stop isolating after testing positive?

This is a controversial one. For starters, here’s what the CDC recommends:

  • If you’ve had no symptoms, you can end isolation after day five.
  • If you’ve had some symptoms, you can end isolation after day five if your symptoms are improving and you are fever-free for 24 hours.
  • If you’ve had moderate symptoms (shortness of breath or difficulty breathing), you need to isolate through day 10.
  • If you were hospitalized or are immunocompromised, you need to isolate for at least 10 days, and talk with your doctor about isolating for longer.

Not everyone agrees with that. A few experts offered a simpler but more conservative option: waiting until you test negative on a rapid test to leave isolation. An even more conservative approach would be to wait for two negative tests.

Rapid tests are a solid, if imperfect, gauge of your lingering contagiousness postinfection. As long as you’re still testing positive, there’s a chance you’re still contagious (but also a chance you aren’t).

6. If you (like President Joe Biden) experience a symptom rebound after taking Paxlovid, do you need to go back into isolation? And, if so, for how long? Does the clock reset?

Yes, and the clock does reset. Researchers don’t have a ton of data on rebound contagiousness yet, but Wachter told me he’s seen “several examples” of people who infected others during their second leg of symptoms.

“This is the million-dollar question,” Katelyn Jetelina, an epidemiologist who writes the newsletter Your Local Epidemiologist, told me over email. “We hypothesize that people are infectious during a rebound, but we don’t have the data to know for sure yet. To me, the golden rule is that if you’re testing positive on an antigen test, assume you’re contagious.”

If it’s any consolation, Sax supposes that some of those who experienced rebounds might’ve been destined to have had a long stretch of positivity either way—Paxlovid just cut them a break in the middle.

7. If you’re still testing positive for COVID after day 10, are you still contagious?

We can’t know for sure. As Wachter explained: “If you’re still testing positive, there’s still a possibility that you’re still infectious, and there’s no good practical way to know whether you are or aren’t.”

So should you stay isolated? Different experts had different opinions on what to do. This late in the game, Chin-Hong said, he doesn’t recommend testing—and doesn’t worry about infectiousness too much, citing pre-Omicron studies that showed no transmission after day 10. Two exceptions, he told me, are if you live with someone who is immunocompromised or work with vulnerable populations. In those cases, you probably want to be extra careful.

“If it were me or a family member, I would say it’s okay to leave isolation on day 11, but you should wear a good mask and assume you might still have a small amount of virus and that you’re capable of infecting someone,” Wachter suggested. When Wachter’s wife had a symptom rebound on day 13, they watched TV together with N95 masks on.

Jetelina pointed back to her golden rule: If you’re still testing positive, assume you’re contagious.

8. How long do people typically keep testing positive for COVID on at-home tests?

The average person turns negative on about day eight. But that doesn’t mean everyone will. Wachter told me the distribution is “a reasonable bell-shaped curve,” with some people testing negative sooner and some taking much longer to clear the virus.

9. While sick, can you use a pulse oximeter to monitor your oxygen levels?

Sure, with a few caveats. These devices, which run about $40 at pharmacies, allow you to monitor the oxygen saturation in your blood. A low reading may suggest you need further care. “The magic number we generally use is 93,” Chin-Hong told me. If your blood oxygen reaches that level, then “you should definitely get in touch with somebody.”

However, know that the devices aren’t perfect. Sax notes that they may overreport low values, which could become cause for unnecessary panic, and so he mainly recommends them for people at high risk of severe outcomes. They also may be less accurate for people with darker skin.

10. Should everyone get the new bivalent booster shot?

The updated formula is based on two new subvariants of Omicron. Experts do recommend that pretty much everyone gets it—unless you’ve had COVID or a booster within the past three months. Boosters in general have proved effective at preventing severe disease, Wachter said, and the new formula is expected to be even better. (Although we don’t know how much better.)

Timing is another matter. “Whether or not you rush out and get it all depends on who you are,” Chin-Hong told me. People who are older than 60 or immunocompromised or haven’t gotten a booster in 2022 should go “sooner rather than later,” he said. Everyone else can consider strategically scheduling their jab to maximize its potency. For a more in-depth breakdown on what to consider when planning your fall booster, read this story by my colleague Rachel Gutman-Wei.

11. Is it okay to get the booster at the same time as your flu shot? Any reason to wait on either?

Yes, and maybe. The only reason to wait on your flu jab, Sax says, would be to better time it for flu season, which usually peaks in the winter. “I typically recommend people get their flu vaccine when they start seeing Halloween candy being sold,” he said. Older people, in particular, may want to consider waiting on the flu shot a little longer, because their immunity may wane more quickly, Jetelina told me.

If you do decide to hold off for a few weeks, just be sure you return to get your flu shot: If you think you might forget, experts recommend just getting both at once.