COVID-19 and your health

Reinfection with SARS-CoV-2, the virus that causes COVID-19, means that a person was infected, recovered, and then reinfected. An individual can be reinfected several times. Re-infections are usually mild, but serious illness can occur. People who get reinfected can also spread the virus to other people. Keeping up with vaccinations and starting treatment within days of developing symptoms decreases a person’s risk of severe illness from reinfection.

After SARS-CoV-2 infection, people’s immune systems respond to protect them from SARS-CoV-2, including by making antibodies. This immune response can provide a high level of protection against infection with the same or other SARS-CoV-2 variants for several months, but this protection wanes over time. People with weakened immune systems may have a limited or even no immune response after infection. Protection against severe disease from COVID-19 generally lasts longer than protection against SARS-CoV-2 infections in general.

As the virus evolves, new variants with the ability to evade a person’s existing immunity can appear and lead to an increased risk of reinfection. Re-infections can occur during the first 90 days and as soon as several weeks after the previous infection, although this does not happen often. This risk of early reinfection can increase when new variants emerge.

Re-infections will occur more frequently as the number of people with a history of prior infection increases and immunity from prior infection or vaccination wanes over time. Reinfections are a common feature of many respiratory viruses.

COVID-19 tests for people with a recent history of infection

While the test is easy, interpreting test results in the first 90 days after a previous infection can be challenging. CDC has developed test guide explaining what type of test people should take in different circumstances.

Nucleic acid amplification tests (NAAT), such as polymerase chain reaction (PCR), are often more sensitive than antigen tests; however, they are not recommended for detecting a new infection when someone has been previously infected with SARS-CoV-2 within the past 90 days. This is because people can still test positive using a NAAT for several weeks after infection, even when they are no longer infectious or experiencing symptoms. This makes it difficult to determine if a positive NAAT test indicates a new infection. If you have tested positive for COVID-19 in the last 90 days and are testing for a possible new infection (i.e., reinfection), consider using an antigen test or seeing a health care provider.

Protecting Yourself and Others: What You Can Do

If you have been exposed to the virus that causes COVID-19, you should continue exposure guide, regardless of your vaccination status or whether you have had a previous infection. For those who have been previously infected, vaccination offers additional protection, especially against reinfection leading to hospitalization. The CDC recommends that people 6 months and older, including those with previous infections, to be up to date with COVID-19 vaccines.

Specific COVID-19 prescription drugs and treatments are available to those eligible, regardless of vaccination status or if they have had a prior infection. People with symptomatic COVID-19 and risk factor’s that make them more likely to get severely ill from COVID-19, they should start treatment as soon as possible, regardless of whether they have had a previous infection. If you do not have a health care provider, visit a Test location to treat or contact your local community health center or health department.

What the CDC is doing

We continue to learn more about reinfections, especially as new variants of SARS-CoV-2 emerge.

Centers for Disease Control and Prevention is working with multiple partners and using a variety of data sources to better understand important knowledge gaps around reinfections, including:

• who is at higher risk of reinfection, especially those leading to hospitalization;
• how soon reinfections occur after a previous infection;
• how severe reinfections are compared to initial infections; and
• is reinfection associated with the risk of worse outcomes or complications in the acute or long phase of covid