How many fully vaccinated people can gather in a home without masks?
For the fully vaccinated, life is starting to look a bit more normal. This month, the U.S. Centers for Disease Control and Prevention updated its guidelines to say that fully vaccinated people can resume domestic travel for pleasure. The agency also says it’s now OK to hang out with other vaccinated people indoors without social distancing or masks. The guidance is based on new evidence that suggests vaccines are not only effective at preventing illness from the virus, but also at stopping its spread.
Still, we’re not out of the woods. Only 20% of the U.S. population is fully vaccinated. And while the shots appear extremely effective at preventing Covid-19, they aren’t 100% effective. That’s why we’ve seen headlines in recent weeks about some vaccinated people getting infected, and we need as many people as possible to get inoculated. That way, there won’t be enough hosts for the virus to replicate widely.
If you’re vaccinated and hanging out with a small group of other vaccinated people, your chances of getting exposed to the virus are extremely low. The bigger the group, the bigger the risk. If you’re, say, at a concert, theme park or a party where there’s lots of unvaccinated people as well, the odds of remaining virus-free get worse and worse.
“The guidelines on gatherings emphasize the importance of understanding the risk of the gathering based on number of cases in the community, exposure of attendees while traveling to the event, type of ventilation at the event, length of the event, ability to maintain physical distance at the event and behavior of attendees at the event,” says Jessica Justman, an infectious-disease expert at Columbia University.
The CDC advises that even fully vaccinated people continue to practice social distancing and mask-wearing in public or around unvaccinated people from multiple households. It also advises avoiding medium- and large-sized in-person gatherings in general.
“As a rough guide, I would say up to about 10 fully vaccinated people meets my definition of a ‘small’ gathering, but this depends on the size of the indoor space,” says Justman. “ Even for a small gathering of fully vaccinated people, I would still be more comfortable keeping the social distances a bit further apart then we did under ‘normal’ conditions. This means that 10 fully vaccinated people, without masks, packed into a tiny room for a couple of hours would not meet my definition of a small gathering.”
If you’re fully vaccinated but have regular close contact with unvaccinated people who are at high risk of having a severe case of Covid, Justman recommends skipping even small indoor gatherings to protect them.
It all comes down to the math. What’s your personal risk, and what’s the risk of all the people around you? So, if you’d like to go on vacation or spend an afternoon at the movies or go see a summer concert, the best course of action is to encourage your friends and family to get their shots.
