Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
UPDATE
Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.
UPDATE
The White House announced that vaccines will be required for international travelers coming into the United States, with an effective date of November 8, 2021. For purposes of entry into the United States, vaccines accepted will include FDA approved or authorized and WHO Emergency Use Listing vaccines. More information is available here.

What Is COVID-19 Reinfection?

What Is COVID-19 Reinfection?
Updated Apr. 29, 2024
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This information is intended for a general audience.

Reinfection with the virus that causes COVID-19 occurs when you are infected, recover, and then get infected again. You can be reinfected multiple times.

Reinfections are most often mild, but severe illness can occur. If you are reinfected, you can also spread the virus to others. Staying up to date with COVID-19 vaccines and treating COVID-19 illness within a few days of when symptoms start decrease your risk of experiencing severe illness.

Once you have had COVID-19, your immune system responds in several ways. This immune response can protect you against reinfection for several months, but this protection decreases over time. People with weakened immune systems who get an infection may have a limited immune response or none at all. Protection against severe COVID-19 illness generally lasts longer than protection against infection. This means even if you get infected again, your immune response should help protect you from severe illness and hospitalization.

As the virus evolves, new variants with the ability to evade your existing immunity can appear. This can increase your risk of reinfection. Reinfection can occur as early as several weeks after a previous infection, although this is rare.

COVID-19 Testing for People with a Recent History of Infection

Interpreting new positive test results in the first 90 days after a previous infection (that is, to identify a possible reinfection) can be challenging. CDC has developed testing guidance explaining which type of test you should take under different circumstances.

Protecting Yourself and Others – What You Can Do

CDC recommends that all people use core prevention strategies to prevent COVID-19 and other respiratory viruses, including if you have previously had COVID-19.

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