a positive home antigen rapid test

The short answer is yes, though it’s not common.

We’ve known for some time that reinfection of COVID-19 is possible, and you probably know someone who has had COVID-19 more than once. Having had COVID-19 before and vaccination each provide protection against getting COVID-19 again. However, your risk of getting COVID-19 again depends on which variants are circulating through our community. This is why it’s so important to get your bivalent booster to further protect yourself against the Omicron variants!

The majority of reinfections occur at least 90 days after the initial COVID-19 infection. But through genomic sequencing, scientists learned that early reinfection—getting COVID-19 again within 90 days—is possible. With genomic sequencing, scientists analyze the genetic material of the virus that made a person sick. In this study, which included participants from Wisconsin, scientists learned several people were infected with two different variants with less than 90 days between their infections.  


It’s been less than 90 days since I had COVID, but I have symptoms again. What do I do?

We count “less than 90 days” from the day your symptoms first started or if you never had symptoms, from your test date.

You can get tested to see if you have COVID-19 again. Molecular tests (like PCR or NAAT tests) can detect past infections for up to 90 days, so we don’t recommend them if this is your situation. If you took a molecular test right now, we wouldn’t know if you’re still testing positive from your first infection or a new infection.

If it’s been less than 30 days since your last infection

  • It may be difficult to tell if another positive test within 30 days of being sick with COVID-19 means you have a new infection. Antigen tests, including home tests, can sometimes detect an infection for several weeks after you have recovered. If you took an antigen test now, it could still be positive from your first infection.
  • If you have been exposed to someone with COVID-19 within 30 days of your last infection and have symptoms, we recommend:
    • Staying home until your symptoms begin to improve (if you had a fever, wait at least 24 hours after you are fever free to be around others) and
    • Wearing a high quality, well-fitting mask when around others for 10 full days after your exposure.
    • Talking to your doctor if you have any questions or concerns about your individual circumstances.

If it’s been more than 30 days since your last infection

  • Use an antigen test (such as a rapid home test) if it has been more than 30 days since your last infection.
  • You may need to take more than one antigen test to get an accurate result. The FDA explains more.
  • You can read more about choosing a test on the CDC’s COVID-19 Testing page.

What should I do if I am exposed or reinfected within 90 days of my last infection?

Regardless of whether you’ve been exposed or infected in the past, if you have a new exposure to someone with COVID-19, you should wear a high quality, well-fitting mask when around others inside your home or in indoor public spaces for 10 full days after your exposure.

If you’re exposed to someone with COVID-19 and…

  • It has been more than 30 days since your last infection, take an antigen test (such as a rapid home test) at least 5 days after your exposure.
  • It has been more than 90 days since your last infection, take an antigen or molecular test at least 5 days after your exposure.
  • If you develop symptoms at any time after a recent exposure, isolate at home and get tested. When using home tests, you may need to take more than one test—the FDA explains why
  • If it’s been 31-90 days since your last infection, and you test positive for COVID-19 with an antigen test or your doctor diagnoses you with a COVID-19 reinfection, isolate at home for 5 full days (day 0 being the day your symptoms started or the day you were tested if you had no symptoms). After ending isolation, wear a high quality, well-fitting mask when around others through day 10.

You can read more on our What to Do if You’re Sick or Were Exposed page.

This content is free for use with credit to the City of Madison - Public Health Madison & Dane County and a link back to the original post.