It seems like everyone has a “summer cold” these days. If you have hallmark COVID symptoms — headache, runny nose, sore throat, sneezing, coughing — but your at-home test says you’re negative, what do you believe: your body or the test?
There are a few possibilities in this scenario, experts say Fortune. At-home COVID tests “work as well as ever” – even on new variants like “Pirola” BA.2.86, “Eris” EG.5.1 and “Fornax” FL.1.5.1, Dr. Amesh Adalja, an infectious disease specialist and senior scholar at the Johns Hopkins Center for Health Security, explains Fortune.
Your test may have given you a false negative, which is much more common than false positives, experts say.
It could also be that you are performing the test incorrectly, or at the wrong time.
Are you doing your COVID test incorrectly?
One reason you may test negative when you don’t: When you performed your nasal swab test, you may have swabbed a sample of your nose that did not contain the virus. Or maybe the patch contained the virus, but not enough.
“When we take a nasal sample, we’re picking up a small sample – a very small surface area – when the virus could certainly be replicating somewhere else in the body,” says Dr. Stuart Ray, vice chairman of medicine for data integrity and analytics at Johns Hopkins’ Department of Medicine, previously said Fortune.
“The nose is one of the portals through which the virus enters and lives, but it is also in the mouth and can be deep in the lungs.”
Are you taking your COVID test at the wrong time?
It’s a common complaint these days that at-home COVID tests don’t work, says Raj Rajnarayanan — assistant dean of research and associate professor at the New York Institute of Technology’s campus in Jonesboro, Ark., and a leading tracker of COVID variants – Fortune.
You may be testing too early at home. Both at the beginning and end of an infection, the viral load is not always large enough to make a test positive.
Most people with symptoms who test negative initially “test positive after a day or two,” Rajnarayanan says.
What question will you ask during your COVID test?
The problem for many people is that they ask the wrong question on their at-home COVID test, Adalja says.
While most people use them to determine whether they have COVID or not, such tests can only tell you whether you can spread COVID or not. A negative means you can’t, and positive means you can.
According to Adalja, they cannot tell you with certainty whether or not you have or have had COVID.
Some additional tips for testing, from the U.S. Centers for Disease Control and Prevention:
- If you have COVID symptoms, test immediately.
- If you test negative with a home test, repeat the test again within 48 hours.
- If you have been exposed to COVID, test at least 5 full days after exposure.
- If you test negative with a home test, repeat the test again within 48 hours.
- If you still test negative, wait another 48 hours and then test one final time.
- In both cases, if you prefer not to wait, you can have a PCR or polymerase chain reaction test performed by a doctor. These are more sensitive and usually more accurate.