COVID immunity can last for several months, but there is no single timeline that applies to everyone. Protection against getting infected again tends to decrease over time, while protection against severe illness usually lasts longer.
After a COVID infection, many people develop immune memory that can remain detectable for at least six to eight months. Some studies found protection lasting about a year or longer, especially before the Omicron variants appeared. Immunity may also be stronger when a person has both prior infection and vaccination.
Reinfection is still possible, sometimes even within a few weeks, although this is uncommon. New variants may partly avoid earlier immunity, so a previous infection does not guarantee protection from future infections. The length of protection also varies according to the variant, the person’s immune response, and whether they have been vaccinated.
Vaccination is still recommended after COVID because it can strengthen protection and reduce the risk of severe disease. Basic prevention measures, such as staying home when sick and avoiding close contact with vulnerable people, remain important. Speak with a doctor if you have concerns about vaccination, repeated infections, or a weakened immune system.