Is one form of test superior to another?
Virus tests are classified according to what they look for: molecular tests check for the virus's genetic material, whereas antigen tests hunt for viral proteins. However, comparing quick antigen tests to lab tests (also known as P.C.R. tests) is like to comparing an X-ray to an M.R.I. scan. Both tests are dependable, perform distinct functions, and can be valuable at different times. An X-ray has the advantage of being inexpensive, quick, and effective at detecting evident issues. An M.R.I. takes much longer and costs much more, but it provides a more detailed picture of what's going on in the body.
Rapid antigen tests, whether performed at home or at a testing facility, have the benefit of being quick, inexpensive, and extremely reliable in determining whether you are spreading the virus right now. A P.C.R. test is more sensitive and will detect an infection sooner, but the result takes longer to obtain. Both tests are useful, but with a fast-spreading version like Omicron, a quick test can lead someone to isolate a few days sooner, protecting others from your germs.
When is the best time to take a quick home test before spending the holidays with family?
Home tests can determine whether you are currently infected with coronavirus. So you should test as near to the time of the meeting as feasible, preferably around an hour or two before everyone arrives.
Dr. Michael Mina, a former Harvard epidemiologist recommends a more limited testing window. He recommends taking the exam in your car approximately 15 minutes before the event, if possible.
While it is critical to test on the day of the event, if you have extra time or extra testing, two tests spread out over a few days are preferable to one. Try having a lab test or taking a quick test a few days before your party, and then test again on the day of the event.
A negative test does not eliminate your risk. However, taking a test reduces the likelihood that someone at your gathering may spread the infection. "A test will not protect you from infection," Dr. Mina explained. "A test will keep you from infecting others."
If you're flying or taking the train, you should do a test the day before to ensure you don't infect your fellow passengers. When you arrive, you should test within two or three days to ensure that you did not pick up the virus during your travels.
Is it possible to overtest?
Yes. Don't test right after an exposure or high-risk gathering and assume you're safe, because the virus can take several days to reach detectable levels. "Doing it too soon is like taking a pregnancy test," Dr. Panagis Galiatsatos, a medicine physician, explained. "Testing too soon means nothing."
If you already have Covid symptoms, the advice changes. In that scenario, you should get tested as soon as possible. Take a quick test the day your symptoms begin, and if it comes out negative, repeat the test a few days later.