In news we’ve all been waiting for, the U.S. Centers for Disease Control and Prevention released a new set of guidelines that say, once you’re fully vaccinated, you can safely resume some activities considered normal pre-pandemic. Most notably, you can gather without masks with other fully vaccinated people.

“We are starting to turn a corner,” said CDC Director Rochelle Walensky in a recent White House news briefing.

More than two million Americans are now getting vaccinated daily. The new CDC guidance is merely the first step in relaxing certain safety measures.

“These are interim, not final recommendations,” says Neil Fishman, chief medical officer of the Hospital of the University of Pennsylvania. “I would caution people not to get frustrated if they change one way or another, and to proceed with caution.”

Advice will evolve as more people get vaccinated, numbers of new cases decline, and data about the vaccine in a real-world setting grow. For now, to protect those who are not yet vaccinated and prevent larger community spread, the CDC still advises wearing a mask and social distancing when in public, whether you’re vaccinated or not. The CDC also says you should avoid medium- and large-sized gatherings and delay domestic and international travel.

» READ MORE: Where can I get a COVID-19 vaccine in the Philly area? Use our lookup tool.

But what’s advisable in private settings is changing. Here’s what to know about safely gathering with others post-vaccination.

If you’re fully vaccinated and your friends/family are too:

You can hang out indoors with a small group of fully vaccinated people without wearing a mask, says the CDC. This means you can invite friends over for dinner, visit your grandparents in their home, or celebrate your birthday with your parents, as long as everyone involved is also fully vaccinated.

What’s considered “fully vaccinated”? Your body needs time to build protection after vaccination. For COVID-19 vaccines that require two shots (Pfizer-BioNTech and Moderna), you should wait two weeks after your second shot until ditching your mask with other vaccinated people. For vaccines that require one shot (Johnson & Johnson’s Janssen), the CDC says it may take about two weeks after your first (and only) shot until you’re protected.

Does this mean I can throw a party with all my vaccinated friends? The answer is probably not.

“Medium and large groups are still considered off-limits, but finding an exact number for ‘medium’ can be a bit of a challenge,” notes Vincent M. B. Silenzio, professor of urban-global public health and of family medicine and community health at Rutgers University. “The emphasis is on keeping it small, which means you might be able to get away with having, say, a birthday party, but it’s really going to be a birthday party of two, or maybe a handful of people.”

The CDC doesn’t define what a “small” vs. “medium” group looks like. But Fishman adds, “These recommendations are geared towards a single, immediate family.”

If you’re fully vaccinated, but your friends/family aren’t:

Not everyone needs to be fully vaccinated for it to be safe to ease up on precautionary measures, says the CDC. You can have a mask-less, indoor hangout under two conditions: You’re gathering with unvaccinated people from only one other household, and no one in that household (or anyone they live with) has an increased risk for severe illness from COVID-19.

The idea here is that the smaller the number of people involved, the less chance that anyone becomes exposed, including to variant strains that weren’t initially tested against the vaccine. If you do become infected, the current vaccines appear to be highly effective at preventing severe illness, hospitalization, and death. So perhaps more important, says Fishman, is the fact that a smaller group means there are fewer unvaccinated people to whom you could potentially transmit the virus. We don’t yet know whether vaccinated people can spread the virus without ever developing symptoms, but it’s being researched.

“When it’s a single single set of people, the risk to you and them are low, but when you add another set of people, it’s like Russian roulette,” says Silenzio. “The more times you pull the trigger, the more likely you’re going to end up in trouble.”

Even with a single household of unvaccinated people, Fishman advises staying mindful. “My concern is how do you know for certain that someone is or is not at risk of severe COVID-19,” says Fishman.

This puts the onus on the unvaccinated people to communicate their medical history, which they might not be comfortable sharing.

“Do you not visit someone who’s obese? There are certain broad strokes — people who are older than 65, individuals who are pregnant, people who are immunosuppressed — but the distinction [of who’s at risk of developing severe COVID-19] is not always that cut-and-dry,” says Fishman

Unless you know for sure, it’s OK to visit, but you should wear a mask and socially distance, says Fishman. Prescribed by the CDC, too, those precautions help prevent the worst — infecting someone who’s vulnerable, could end up in the hospital, or worse.

In good news, the guidelines do help to take away at least some of the guesswork of hanging out with friends and family, especially if everyone’s vaccinated.

“Here we have our first tangible outline that lets you know what you can do that you couldn’t do before,” says Silenzio. “I don’t know about you, but hugging someone that’s not in my household, that’s highly appealing.”

Silenzio jokingly adds, “Although, coming from a South Philly Italian family, now I’m running out of excuses not to deal with my family all the time.”

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