How soon after COVID exposure is a person infectious?

June 20, 2022 11:46 AM

It's another covid question! Sorry to add to the pile but the anxiety's high and the google results are pitiful. Looking for official information, anecdata or even just guesses!

Trying to gauge ahead of when tests will be useful if I may have caught covid from my friend yesterday. Here's the timeline, what do you think?

Friend's Boyfriend (double or triple vaxxed) went on a work trip on FRIDAY. Found out today someone from that work trip is Covid positive. He just tested and is also covid positive. He rapid tested the day before and was negative so almost without a doubt he did catch it on Friday.

Friend (triple vaxxed) saw his boyfriend SATURDAY from 6pm-10pm.

Friend saw me (triple vaxxed) SUNDAY from 2:30-5pm. Before this, he took TWO RAPID TESTS. One swabbbing the back of his throat. Both were negative. We ate at a restaurant outdoors but he did pick me up so we were unmasked in his car for approx 20 minutes.

Previous to this outing, I had not seen anyone since Wednesday. I've been hyper cautious the whole time much to my mental health detriment and hoping this isn't the one that gets me.

Based on these timelines anyone have any idea of how likely it is that either Friend or Me got covid from this situation?

All the turnarounds are so tight that I'm hoping Boyfriend was not infectious when he saw Friend but if Friend did get it, that Friend was not infectious when he saw Me.

Friend is looking for a PCR and rapid now but I'm worried if he got infected Saturday night that wouldn't show up on a test yet. And I know a test wouldn't be useful to me until tomorrow night at earliest.

Thanks all!

posted by iguana in a leather jacket to Health & Fitness (8 answers total)

Omicron's incubation period is supposedly two to four days. Since your friend also tested before you met, and the rapid tests are most accurate when someone is infectious, I think the chances are good that you were not exposed.
posted by pinochiette at 12:26 PM on June 20, 2022 [3 favorites]

>Looking for official information, anecdata or even just guesses!

My official information is Rates of laboratory-confirmed COVID-19 hospitalizations by vaccination status, especially with Age-Specific Rates selected. It's important to dwell on the fact that the vaccines are extremely effective at training your immune system.

My anecdata is that every triple-vaccinated person I know experienced Covid (the novel coronavirus) just like they have all the other coronaviruses we've all been catching all our lives, because their immune system had been amply warned.

My guess is that because you're triple vaccinated, it's okay to trust your well-prepared immune system.

>the anxiety's high

>I've been hyper cautious the whole time much to my mental health detriment

For the three kinds of reasons above, I suggest focusing on the anxiety as the real problem. Remember: the most likely outcome — by far, by so far, by so very far — by leaps and bounds — is that you catch COVID and it's completely fine. You didn't do anything wrong. You didn't mess anything up for yourself or anyone else. You're okay. Catching COVID as a vaccinated person is okay. It's extraordinarily dangerous for unvaccinated people in their 80s but that is not you.
posted by daveliepmann at 12:29 PM on June 20, 2022 [12 favorites]

Best answer: It is highly unlikely that you would have been infected through this chain of people. Omicron incubation period is generally at least two days.

So from Friday AM to Saturday 10PM, you have about a day and a half. It's possible that the boyfriend was infected first thing on Friday morning and became infectious by Saturday 10pm, but it's not that likely.

But your friend couldn't have been infected before Saturday 6pm and you only saw them less than 24 hours later, which makes it quite unlikely that they could have been infectious.

In order for you to be infected, two unlikely events would have had to happen together, which is of course even more unlikely. This is not worth worrying about; it's more likely for you to get infected through someone else even if you are being relatively careful.
posted by ssg at 12:40 PM on June 20, 2022 [2 favorites]

If anecdata and guesses are welcome, I’ll share. My work puts me in contact with a lot of people who tested negative that morning. Cases in my workplace are infrequent, and seem to mostly come from known outside exposures (ie weekend weddings, etc).

Personally if I were you, I would limit my exposure to others for a few days just in case (stay home, N95 mask when you’re near anyone)… but I would not be too worried in your shoes. When a person is testing negative, I think most sources seem to agree that they likely don’t have enough viral load to infect someone else.

For upcoming situations, I would advise you to keep car windows open! Being in shared enclosed air space is one of the main covid risk factors, and cars are pretty small.
posted by nouvelle-personne at 1:31 PM on June 20, 2022 [2 favorites]

I hung out with friends outdoors on a Saturday. We had all tested beforehand. One of them started having symptoms and tested positive on Sunday. I started having symptoms on Monday and tested positive on Wednesday. It is best to assume you may have been exposed, watch for symptoms, and test for the next few days. Sorry. It fucking sucks.

(I was quadruple vaxxed. As an immunocompromised person, I was able to access Paxlovid and still got incredibly sick and lost 2 weeks of my life to complete misery. Today is day 35, and I'm feeling mostly okay except for the lingering cough and fatigue. It remains best to not get COVID. It is not "a bad cold".)
posted by hydropsyche at 1:52 PM on June 20, 2022 [13 favorites]

I can give you my ancedata but there's really no way to predict anything, Covid is so varied. I'm triple vaxed and always wear a mask when I am inside (grocery shopping is all I do indoors). Still, somehow I got it and began experiencing strong symptoms suddenly on Monday. 1 rapid tests on Monday and Tuesday, both negative but I was really sick so quarantined. Finally tested positive with a pcr on Wednesday. My Dr thinks I was exposed on Thursday or Friday, so 3-4 days till symptoms. My husband (quadruple vaxed, the 4th just a week before) did not get it, thankfully, even though we were together all weekend, mostly indoors. I'm 63, but very healthy and it was really bad for 3-4 days, worst I've ever felt, but improved a lot on day 5, and thereafter, feeling normal on day 7. Good luck.
posted by j810c at 5:08 PM on June 20, 2022 [1 favorite]

Something I have been trying to research, but have struggled to find definitive information about, is where the general consensus actually comes from that rapid test positives accurately indicate infectiousness. What we know about omicron is that many people are experiencing symptoms for several days before they test positive (this happened to my partner), and everyone still seems to agree that people are infectious for at least a day before symptoms develop, which would mean that people may be infectious for several days before a positive registers on a rapid test. So while rapid test are still a useful screening tool, they are by no means a definitive measure of infectiousness.

I think what all of this means is that while your likelihood of being infected is on the low side, it is still possible, so yeah: isolate, start doing daily tests Tuesday, and keep it up for a few days if asymptomatic. If you start to experience symptoms, keep testing and isolating for at least a week even if you’re turning up negatives, just in case.

And for the record, since you asked for anecdata, my partner and I are both vaxxed and single-boosted, and I had original recipe Covid in early 2020. I was around my partner 24/7 during his early symptomatic phase with omicron and didn’t isolate from him until he tested positive. I had a sore throat for a couple of days before we isolated from each other, but I tested negative on near-daily tests for two weeks. My partner continued to test positive every day for 14 days, then negative for a day, then positive again, before finally testing negative on repeated days. ¯\_(ツ)_/¯
posted by CtrlAltDelete at 8:03 AM on June 21, 2022 [2 favorites]

Response by poster: Wanted to give an update for posterity if anyone references this post in their own anxiety spirals:

Friend tested NEGATIVE on a rapid Monday, June 20th
Friend tested NEGATIVE on a rapid Tuesday, June 21st. Friend also tested NEGATIVE on a PCR Tuesday June 21st
Friend tested NEGATIVE on a rapid Wednesday, June 22nd
Friend tested NEGATIVE on a rapid Thursday morning, June 23rd
Friend tested POSITIVE on a rapid Thursday evening, June 23rd

He started to have mild symptoms mid-day Wednesday but originally wrote them off as being caused by something else. Taking that long to show up positive on a rapid test does gives me some concern going forward at how useful the tests in general are.

He spent time with his roommate (triple vaxxed) Tuesday evening after receiving the negative PCR test. She tested POSITIVE on Friday, June 24th. So far all of them have mostly experienced mild symptoms - mostly fatigue and congestion.

I have thus far tested NEGATIVE - just took a rapid now on Day 11 from exposure. Hopeful that I'm past the point of reasonably testing positive from that exposure. Fingers crossed!

Thanks all for the thoughts, I appreciate you taking the time!
posted by iguana in a leather jacket at 2:27 PM on June 30, 2022 [2 favorites]