Question: My stepdad has (had?) breakthrough COVID and while he’s more than two weeks out from first symptoms, I’m not sure whether it’s safe to be around him. (He’s supposed to care for our unvaccinated 2 year old indoors this Friday and two days next week). His first and only symptom (loss of taste) was on 8/29. He PCR-tested positive for COVID 9/7; retested positive on 9/10. I’ve read that dead or inactive viral particles can cause a positive result when the person isn’t actually infectious. I’ve also read that it’s possible some people may be carriers shedding virus for an indefinite amount of time after they become infected. I think we’ll play it safe and seek alternate care this week, but wondering if you have thoughts…

Answer: If your stepdad is not immunocompromised and has not had a serious case of COVID, it should be fine for him to care for your unvaccinated 2-year-old.  Here’s the scoop:

1. Your stepdad meets CDC’s criteria for ending isolation. CDC Guidelines recommend that for non-immunocompromised individuals who have NOT had severe COVID, a person can end isolation if the following three criteria are met: 1) 10 days have passed since symptoms first appeared; AND 2) 24 hours have passed with no fever without the use of fever-reducing medications; AND 3) Symptoms are improving.  CDC also notes that the loss of taste or smell can linger for weeks or even months and “need not delay the end of isolation.”  Also note (unrelated to your example, but still of potential interest)– for individuals who test positive but remain asymptomatic, CDC recommends that isolation be discontinued 10 days after the first positive test.
2. Vaccinated people with breakthrough infections have shorter infectious periods. As CDC describes, “like other variants, the amount of virus produced by Delta breakthrough infections in fully vaccinated people decreases faster than in unvaccinated people. This means fully vaccinated people are likely infectious for less time than unvaccinated people.”  This statement is based on recent studies, including this one out of Singapore.
3. Strategy for ending isolation should be symptoms-based rather than test-based. Per CDC’s Interim Guidance for Ending Isolation, “Available data suggest that patients with mild-to-moderate COVID-19 remain infectious no longer than 10 days after symptom onset.”  Even patients who are no longer infectious can continue to have detectable SARS-CoV-2 RNA in specimens for up to 3 months after illness onset– in concentrations much lower than during illness and in forms that are “not replication-competent” (e.g. not transmissible).  For these reasons, CDC does not recommend a test-based strategy to end isolation among mild/moderate cases who are not immunocompromised. Note: the guidelines do not apply to immunocompromised individuals and if you’d like to read more on that front, the Interim Guidance contains the details.