The Thanksgiving bouncers

• You may have relatives who aren't vaccinated (or won't say) — or babies or immunocompromised guests who are vulnerable to breakthrough infections.

How it works: If you're hosting, let your guests know ahead of their arrival that you'll be testing everyone at the door for their own safety. If you're a guest who's anxious about attending without testing, talk to your host now about their plans and how you can help.

• Depending on your budget, you might offer to pick up the tab for everyone's tests, or hosts might ask guests to pay for their own.
• At-home antigen tests cost around $25 for a box of two.
• Alternatively, guests who have gotten a PCR test within a couple of days prior could bring evidence of their negative results. PCR rapid tests can be obtained same-day but are generally much more expensive.

The other side: Rapid antigen tests overall aren't quite as accurate as PCR tests. In theory, a false positive could leave guests out in the cold (or quarantined in a bedroom) while a false negative could give an undue sense of security.

• But false results aren't common, Gigi Gronvall, an immunologist by training and is a senior scholar at Johns Hopkins Center for Health Security, told Axios. "If you perform the test correctly, you should feel confident if it's a positive, it's a real positive."
• Since the rapid antigen tests are less sensitive than PCR tests, a negative result might simply indicate a person doesn't have enough replicated virus to test positive yet.
• "If you are negative, you can draw some comfort in that but it doesn't mean you'll always be negative. You just might be below the threshold. But you also might not, at that moment, be as much of a danger to somebody else either," Gronvall said.
• One extra precaution may be to purchase enough tests for a re-test, or to ask guests to test on their own before and then again when they arrive for the meal.

But, but, but: "If you are symptomatic, if you have been exposed to somebody with [COVID], I would recommend that you get the gold standard PCR test," Leana Wen, an emergency physician and public health professor at George Washington University, told Axios.

• "But if you don't have any symptoms and you're using this test to find out, 'Should I hang out with this group of people today or not?', the rapid antigen test is very good for that kind of screening purpose."

Between the lines: Beyond requiring tests for entry, there are other tweaks that can help make Thanksgiving a bit safer.

• Opening windows to improve air circulation only goes so far because people want to be comfortable, Gronvall said.
• Those with electronic thermostats can improve airflow by setting their fan to "on" versus "auto" and replacing air filters on their heating systems with MERV Rating 13 filters.
• People can also purchase portable HEPA air filtration devices at hardware stores or national retailers or create their own filtration devices using a box fan, Gronvall said.

The bottom line: Enforcing testing rules at your holiday gathering can reduce the chances of COVID spread. But there's no way to eliminate the risk when people are gathering.

• "Tests are a moment in time, and no test is going to give perfect visibility into whether or not you're infectious," Gronvall said.