The protection someone gains from having an infection (called “natural immunity”) varies, depending on the disease. It also varies from person to person. Because this virus is new, we don’t know how long natural immunity might last. Current evidence suggests that getting the virus again (reinfection) is uncommon in the 90 days after the first infection with the virus that causes COVID-19.
We won’t know how long immunity lasts after vaccination until we have more data on how well COVID-19 vaccines work in real-world conditions. Experts are working to learn more about both natural immunity and vaccine-induced immunity.