Information about the novel coronavirus (the virus that causes COVID-19) is constantly evolving. We will refresh our novel coronavirus content periodically based on newly published peer-reviewed findings to which we have access. For the most reliable and up-to-date information, please visit the CDC website or the WHO’s advice for the public.
If you need same-day COVID test results, your best bet may be a rapid antigen test. These tests look for the outer shell of the virus. They don’t require any special machinery to be processed, so results can be available in minutes (Sakamoto, 2018).
The test typically uses a simple test strip that changes color when the virus’s outer shell is present in your sample. And while you may have heard that these tests aren’t as good at finding the virus as other types, researchers have found that this may not be a bad thing. Here’s why.
When you are infected with the coronavirus, you’re most likely to infect other people in the three days before the symptoms appear (when you don’t even know that you’re sick). After the symptoms appear, the amount of virus in your body starts to go down, so each day that passes makes you less likely to infect others. But even when you’re no longer capable of spreading the coronavirus, your PCR will still be positive. Rapid antigen testing is good at detecting the virus during a person’s most infectious days, and that’s what matters most when it comes to preventing the spread (CDC, 2021).
There are a few different types of COVID tests, and you may not always have a choice about which one you get. Antigen tests and PCR are diagnostic tests—they will tell you if you have coronavirus in your body right now. Antibody tests, however, aren’t used for diagnosing COVID. They detect your immune system’s response to the virus, so they’re used to determine if you had COVID in the past or were vaccinated (FDA-a, 2021).
- If you need same-day COVID test results, look for something called a rapid antigen test. Results take about 15-30 minutes. These tests are available at certain clinics and pharmacies, or can even be done in the comfort of your own home. Both antigen tests and PCR tests can be done quickly, but PCR tests have to be processed in a lab, so it takes a little longer to get your result. If you’re experiencing symptoms of COVID, consult with a healthcare provider. To find a COVID test near you, reach out to your healthcare provider, a local urgent care clinic, or the health department in your state.
How long do the results of each test take?
PCR tests (which look for the virus’s genetic material) and antigen tests (which look for the virus’s outer shell) are pretty quick. But since PCR tests need to be evaluated using a special machine, they can take longer to process.
PCR machines are typically available in hospitals but aren’t usually found in urgent care clinics, pharmacies, or a healthcare provider’s office. Some places can get results quickly, but in other cases, people have waited nine days or longer to get results (NPR, 2020).
You’ve probably seen pregnancy tests where you have to pee on a stick to see if you’re pregnant. Rapid antigen tests are very similar to this. But with rapid antigen tests, you usually collect your sample with a nasal swab. You then put the swab into a small plastic tube that contains a special liquid, and the test strip is dipped into the tube. The whole process takes somewhere between five and 30 minutes to get results (Gugliemli, 2020).
More recently, at-home tests have become available. But not all tests are created equal. Some tests can be done entirely at home (like the Ellume test). Others have you collect the sample at home but send it to a laboratory for analysis (like the Pixel test). Some at-home tests require prescriptions, while others are available over the counter. New tests are made available as they are approved for emergency use by the FDA (FDA-b, 2020; FDA-c, 2021).
When do you need same-day results?
Getting your results quickly is always a priority. While waiting for results, a person might continue to infect others. By the time a positive result arrives, it can be hard to remember all of the people you may have interacted with to alert them that they need to get tested. In extreme cases when people have waited longer than a week to get their results, they’ve been of little or no use at all.
If you’ve been asked to get a COVID test (like if you’re traveling somewhere and the airline requires it), you can search for a testing site that might be able to provide you with that service. Keep in mind though that a negative test isn’t a guarantee and it’s still not a good idea to meet with people without masks — especially not with people who are unvaccinated. As the vaccine rollout continues, it’s important to get both shots before meeting up with other people.
If you haven’t been able to get a shot yet, look at your local government website to find out where you can sign up. Until you’re vaccinated, it’s important to continue to wear a mask when you need to go out and make sure to continue to socially distance when you’re in the presence of people who are not part of your immediate household (CDC, 2020).
What you should do while you wait for the results
If you’ve had a known exposure to a person who tested positive for the coronavirus, or if you’re feeling sick, you need to isolate. This means staying home and staying away from other people in your own household, if possible, especially if you’re feeling sick (CDC, 2020).
If you have symptoms of COVID, consult with your healthcare provider before getting a test. People with mild symptoms may be asked to stay at home and isolate rather than risking exposing others by leaving the house for a test.
Even if you’ve been vaccinated, there’s still a small chance that you could catch coronavirus. Make sure to isolate until you receive your negative test results.
What should I do if my test is positive?
According to the Centers for Disease Control and Prevention (CDC), if you test positive for the coronavirus, you should isolate at home, including from the people in your own household, if possible. It’s okay to stop isolating once (CDC, 2020):
- At least 10 days have passed since your positive test if you did not have any symptoms.
- At least 10 days have passed since your symptoms first appeared.
- You have been fever-free for at least 24 hours without using fever-reducing medication
- Any other COVID symptoms you have are improving
It’s important to know that loss of taste and smell may persist for weeks or months after recovery, and are not a sign of being infectious. If you’re not sure, consult with a healthcare provider before you stop isolating.
- Centers for Disease Control and Prevention (CDC). (2021, July 19). COVID-19 Quarantine and Isolation. Retrieved September 8, 2021, from https://www.cdc.gov/coronavirus/2019-ncov/your-health/quarantine-isolation.html
- Guglielmi, G. (2020, September 16). Fast coronavirus tests: What they can and can’t do. Nature News Feature. Retrieved January 12, 2021, from https://www.nature.com/articles/d41586-020-02661-2#:~:text=Antigen%20tests%20give%20results%20in,with%20a%20cost%20in%20sensitivity
- NPR: Feldman, N. (2020, June 16). Philly officials want you to get tested for COVID. People trying say it’s not easy. Retrieved January 11, 2021, from https://whyy.org/articles/philly-officials-want-you-to-get-tested-for-covid-those-who-have-tried-say-its-not-that-easy/
- Sakamoto, S., Putalun, W., Vimolmangkang, S., Phoolcharoen, W., Shoyama, Y., Tanaka, H., & Morimoto, S. (2018, January). Enzyme-linked immunosorbent assay for the quantitative/qualitative analysis of plant secondary metabolites. Retrieved January 12, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5775980/#CR7
- U.S. Food and Drug Administration (FDA)-a. Center for Devices and Radiological Health. (2021). EUA Authorized Serology Test Performance. Retrieved September 8, 2021, from https://www.fda.gov/medical-devices/coronavirus-disease-2019-covid-19-emergency-use-authorizations-medical-devices/eua-authorized-serology-test-performance
- U.S. Food and Drug Administration (FDA)-b. (2020, December 15). Coronavirus (COVID-19) Update: FDA Authorizes Antigen Test as First Over-the-Counter Fully At-Home Diagnostic Test for COVID-19. Retrieved January 11, 2021, from https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-antigen-test-first-over-counter-fully-home-diagnostic
U.S. Food and Drug Administration (FDA)-c. Coronavirus (COVID-19) Update: FDA Authorizes Antigen Test as First Over-the-Counter Fully At-Home Diagnostic Test for COVID-19. Retrieved September 8, 2021 from https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-antigen-test-first-over-counter-fully-home-diagnostic