COVID-19 tests: what you need to know

Rapid at-home COVID-19 antigen tests are used to detect live  coronavirus infection in the body.

rapid at-home COVID-19 antigen tests

Sometimes these tests aren’t perfect, but even a faint line is considered a positive result.


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What do at-home tests measure?

Rapid at-home COVID tests are looking for a protein found on the COVID-19 virus. The protein is called an antigen, and that is what triggers our bodies immune response. That’s why the at-home tests are also called antigen tests. Read more on it here.

At-home COVID-19 tests work similarly to a pregnancy test, a pink line appears to show if the antigen is present. The test is completed by swabbing each nostril and then placing the swab in a reader or solution, and then poured on a strip. Your result will then be available in 10-15 minutes.

The test should be marked C (Control) and T (Test). When the test is done correctly, the C line will show up. If the C line does not appear, the test has failed and you should administer a new one.

If the T line appears, coronavirus antigens have been detected. The T line indicates a positive COVID-19 infection.

Positive at-home tests do not need to be reported to any public agency in the United States. However, you should tell your doctor. You can also go to a testing center to confirm you positive result.


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Reliability of at-home tests

If you are contagious and have an active infection, at-home rapid antigen tests are considered reliable.

New contraction of COVID-19 may result in a negative test, but a positive one just days later.

If you have doubt, test more frequently. A singular at-home test cannot confirm a case of coronavirus. Two tests over a three or four day period could confirm a case.

CDC says that the best testing window is three to five days after a high-risk event. This means you have the best chances of testing positive 3-5 days after you may have been exposed.


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