It can help if you get results quickly enough. And if you trust the results. If I came into close contact with someone who tested positive I wouldn't trust a

It can help if you get results quickly enough. And if you trust the results. If I came into close contact with someone who tested positive I wouldn't trust a negative test. If I had no symptoms I'd quarantine for 10-14 days. For people with tertiary exposure, through me, I have no idea how they should handle it.