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1/ I've seen that a lot of you think rapid antigen tests can keep your Thanksgivings safe. But it’s not that simple. These tests have been known to give false positives AND false negatives. Doesn’t mean you can’t gain anything from them.
Here’s what you need to know:
Here’s what you need to know:
2/ Antigen tests are faster + cheaper than lab-based PCR tests. They’re also less accurate. BUT: they’re good at catching people who are most likely to infect other people.
3/ That’s the main argument for antigen testing: when used widely, they can flag many people with high viral loads, which is also when they’re most infectious. So if they miss some people, it’s ok—because you’ve lowered cases overall. However…
4/ Nobody wants to be that person who gets a false negative or false positive on an antigen test. No test is perfect, but here are some things you can do to increase confidence in your results...
5/ First, if you have covid symptoms, and you’re within the first 5 days (or first week) of symptoms, a positive result from an antigen test is very trustworthy. If you test negative, wait a couple days and get another test to confirm it.
6/ Repeat antigen testing reduces false negatives—but make sure you wait a day or two between tests.
7/ If you don’t have symptoms, it’s trickier. The 3 most popular antigen tests in the US were only authorized by the FDA for use on people within the first 5 to 7 days of symptoms. But the govt has encouraged their use on asymptomatic people, causing confusion.
8/ When a Vermont hospital reported problems with false positives for asymptomatic people, the FDA defended the antigen test. When Nevada nursing homes reported similar problems, a federal official wrote: “Be prepared for some ‘pressure’”
9/ That “pressure” came from an assistant secretary of health at the Dept of Health and Human Services, who threatened Nevada with unspecified consequences until the state agreed to keep using those tests in nursing homes.
10/ It took weeks before the FDA acknowledged that antigen tests are prone to false positives, especially in populations where few people have the virus. So, if you have no symptoms, haven’t taken risks and live in a place with few infections, but test positive...
11/ it could be a false positive. Get a PCR test to confirm it. (PCR tests are useful for weeding out false positives).
12/ Antigen tests could help slow the spread of covid. But they only work well with a coordinated plan—which the govt never provided. Here’s our story on how the govt spent weeks denying problems with false positives: https://www.propublica.org/article/rapid-testing-is-less-accurate-than-the-government-wants-to-admit
13/ Most important: testing alone, no matter how accurate, won’t keep you safe. This @wired story gives a good explanation as to why: https://www.wired.com/story/that-pre-thanksgiving-covid-test-wont-really-keep-you-safe/#intcid=_wired-homepage-right-rail_ca270acf-8eb9-4a91-8da8-7828d495c88b_popular4-1
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