People receive free at-home COVID-19 test kits at a government distribution site on January 02, 2022 in Stamford, Connecticut.

People receive free at-home COVID-19 test kits at a government distribution site on January 02, 2022 in Stamford, Connecticut. John Moore/Getty Images

When Should You Take an At-Home COVID Test?

"If you have COVID-19 symptoms and test positive on an at-home test, you have COVID-19. You don’t need to get another test to confirm the results."

As the very infectious Omicron variant of COVID-19 surges around the country, you need to know what kind of tests to take to protect yourself and your community.

Here, Emily Landon, infectious disease expert and executive medical director for infection prevention and control at University of Chicago Medicine, answers common questions about COVID-19 tests.

These include when to get a COVID-19 test, what kind you should use, what to do if you can’t get one at all, and why it’s still important to get vaccinated and boosted:

Q: When should I get a COVID-19 test?

A: Isolate and get a COVID-19 test if you have any symptoms of COVID-19, even if they’re mild and even if you’re fully vaccinated and/or boosted. Symptoms may include sniffles, congestion, or a cough, and might resemble a mild cold, especially in fully vaccinated and boosted people.

Even if you have minor symptoms, you are still contagious. People who are unvaccinated or immunocompromised may still get severe disease. Stay isolated if you have any symptoms, even if you cannot quickly get a COVID-19 test.

Q: How are rapid antigen tests different from PCR tests? Is one better than another?

ARapid antigen tests, which you can buy in most pharmacies, are great in specific circumstances and less good in others. Rapid antigen tests detect COVID-19 when people have a higher amount of virus particles in their system and are more contagious. But a negative antigen test doesn’t necessarily mean you aren’t contagious.

If someone has COVID-19, but hasn’t yet reached the test’s threshold of viral particles, they may still test negative with an antigen test but positive on a PCR test. That’s why I tell people they should trust a positive antigen test, but be more skeptical about a negative one.

PCR tests, which are still mostly done at hospitals and other testing facilities rather than at home, are far more sensitive than antigen tests. They’re able to detect smaller quantities of the virus and detect them sooner (and for more time) than antigen tests.

While they’re considered the gold standard for a COVID-19 diagnosis, PCR tests are unnecessary for those who have already tested positive on an antigen test. That’s important to know as wait times for PCR tests grow due to increased demand.

In short: any positive test counts as a positive, but a negative antigen test needs to be confirmed with a PCR test.

Q: When should I use an at-home test?

A: A rapid, at-home antigen test is a useful tool to have in your COVID-19 arsenal. But you need to know when and how to use these tests.

Q: What should you do if you have symptoms?

A: If you have COVID-19 symptoms and test positive on an at-home test, you have COVID-19. You don’t need to get another test to confirm the results.

But if you have symptoms and you test negative, you should not rule out COVID-19 just yet. In this case, we recommend getting a more sensitive PCR test. If you can’t get in for a PCR test quickly, it’s recommended to repeat the antigen test the following day, being sure to isolate until you get your PCR test and results. If you can’t get a PCR test at all, isolate for 10 days.

Q: What should you do if you don’t have symptoms?

A: For those without COVID-19 symptoms, using these tests before a gathering will reduce (but not eliminate) the risk that someone attending has COVID-19. Remember: antigen test results can change quickly, and a negative result is really only trustworthy for eight to 12 hours.

In other words, you shouldn’t rely on a negative test in the morning if you want to get together in the evening with friends or family. Make sure everyone who’s attending an event uses an at-home test as close as possible to the time they’re gathering and understands that a negative test doesn’t guarantee safety or completely prevent exposure.

If you’ve had a known COVID-19 exposure, no test is going to make it safe for you to gather unmasked with high-risk individuals. Stay home.

Q: How do I interpret at-home tests?

A: If you’re taking an at-home COVID-19 test, consider any positive result to mean you have COVID-19. You don’t need to confirm with a PCR test. (Even if it’s an extremely faint line, you should consider yourself infected and isolate.) If you’re unclear about what your test result says, isolate and repeat the test in six to 12 hours. You’ll likely see a clearer line on the test strip next time.

Don’t forget: a negative at-home test is only reliable for eight to 12 hours and still doesn’t guarantee you’re COVID-free. You should get a PCR test if you have symptoms.

Q: What should I do if I can’t get a COVID-19 test?

A: Given the widespread transmission of the Omicron variant, if you have symptoms, you should assume you are infected with COVID-19, regardless of your vaccination status. Isolate for the amount of time that’s recommended by the health department.

A negative antigen test doesn’t necessarily mean you aren’t contagious.

Q: What should I do if I’ve been exposed?

A: If you’ve been exposed, but have no symptoms and you are fully vaccinated and boosted, you don’t need to quarantine. But you should get a test on Day 4, 5, or 6 following your exposure. (For example, if you were exposed on Monday, you should get tested on Thursday, Friday, or Saturday.) If you develop symptoms, assume you’re infected and begin isolation.

If you’ve been exposed and are vaccinated but not boosted, you need to quarantine for five days after an exposure and wear masks for another five days after that. You are still at high risk of infection, especially from the quickly spreading Omicron variant.

You should wear a mask around other people, and get tested four to six days after the exposure and anytime you develop symptoms. Avoid gatherings and do your best to limit contact with people who are immunocompromised or who are unvaccinated.

If you’ve been exposed, have no symptoms, but are NOT vaccinated, stay home and quarantine for five days. You’ll need to wear a mask for another five days after that.

Q: I’m vaccinated and boosted. Why did I still get COVID-19?

A: COVID-19 vaccines and boosters are hugely valuable. In addition to providing protection from the virus, vaccines and boosters reduce the chances of serious illness, hospitalization, and death. But people can still get infected when they’re fully vaccinated and boosted. This may be because the vaccine’s protection has decreased over time or because a new variant (like the Omicron variant) is better at getting around the vaccine’s protective properties.

COVID-19 infections in fully vaccinated people are called breakthrough infections, which usually result in milder symptoms versus infections in the unvaccinated. Your body’s memory B cells and T cells, which developed after your vaccine, respond quickly to stop the infection and prevent severe damage.

Immunocompromised people may not have strong B cell- and T cell-immunity even after vaccination, so they remain at higher risk. If you are immunocompromised and have a breakthrough infection, you should contact your doctor even if you only have mild symptoms.

Unvaccinated people don’t have existing antibodies or memory B cells or T cells waiting to fight off COVID-19, so they have to start their immune response from scratch if they become infected. Infections typically cause more damage to their organs and tissues, which can lead to complications like having low oxygen levels, as well as problems with the lungs, kidney, and heart. Unvaccinated individuals are also much more likely to need intensive care support or have lingering symptoms known as long COVID-19.

Q: If I have a breakthrough infection after my COVID-19 vaccine, will I still be contagious for the same amount of time?

A: There’s a good amount of evidence showing most fully vaccinated and boosted people with breakthrough infections are both less contagious, and contagious for a shorter time. They’re also more likely to get mild infections.

Q: Can I report my positive at-home test results to public health officials?

A: At-home antigen test results are not typically reported to public health agencies, nor are they usually included in official case tallies. This means statistics are significantly under-reported. In some communities, local health departments are setting up portals for people to self-report at-home results, but you’ll need to check to see what’s available in your area.

The most important thing to do is stay home and isolate. If you have certain health conditions—especially if you’re immunocompromised—contact your doctor ASAP so they are aware of your diagnosis.

Q: When can I get the new medicine that’s received emergency use authorization to fight or prevent COVID-19?

A: The good news is that new antiviral medication and a preventative monoclonal antibody treatment have received emergency use authorization from the US Food & Drug Administration. They’ll be very important resources for doctors and high-risk patients. Even so, these treatments will be extremely limited at first. They will first be distributed by public health agencies and will only be available to the highest-risk patients.

If you are a transplant recipient, have a primary immunodeficiency, take immunosuppressive medication, or are undergoing active chemotherapy, and you test positive for COVID-19, you should contact your doctor right away to see if any of these treatments are available to you.

Q: Do COVID-19 booster shots offer added protection against the Omicron variant?

ABoosters offer the best protection from catching COVID, but they aren’t perfect. Scientists are still gathering data on the effectiveness of vaccines against Omicron, but existing data show people who are vaccinated and boosted have additional protection and are less likely to be hospitalized than those who are unvaccinated.

Read more about booster shots and third doses here.

Source: University of Chicago

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.