Rapid antigen testing detects if you have enough virus to be contagious. It only takes 15 minutes to get the result and they have a sensitivity of 97% for identifying contagiousness! A COVID test that is relatively inexpensive (BinaxNOW is $7 each), gives rapid results, can be done in the convenience of your home and has a very high sensitivity for detecting contagiousness are what make these such great tools for public health. If a positive result is found, one can quickly quarantine and do a confirmatory PCR test (or repeat rapid test 36 hours later).
We use these in our household (on a weekly basis) to assess for asymptomatic COVID infections that have enough viral load to be infectious.
This is just one more layer of helping to protect our community. Hopefully, in the near future, rapid antigen tests will become much more readily available and less expensive (BinaxNOW tests cost $7 each).
DISCLAIMER: No tests are 100% accurate. While very good, rapid antigen tests can still miss infections in patients who are contagious. Repeating testing after 36-48 hours is recommended by Abbott for their BinaxNOW test, which is why they included two tests in each box.