Do the antibodies against COVID-19 disappear from the blood?

Antibodies to COVID-19 can disappear from the blood over time, but this does not necessarily mean that immunity to the virus disappears completely. The dynamics of antibodies and immunity to SARS-CoV-2, the virus that causes COVID-19, are complex and involve several aspects of the immune system.

After infection with SARS-CoV-2, the body begins to produce antibodies (immunoglobulins), usually within days to weeks. IgM antibodies appear first and usually disappear after a few weeks. IgG antibodies develop later and tend to persist longer in the blood.

Studies have shown that IgG antibodies to SARS-CoV-2 can decline several months after infection. A study published in "Nature" found that IgG antibody levels typically begin to decline within 3 to 6 months after infection.

In addition to antibodies, the immune system plays a role in long-term protection in other ways. Memory B cells and T cells can recognize SARS-CoV-2 and respond quickly to re-exposure to the virus. Memory B cells can quickly produce new antibodies upon reinfection. T cells help destroy infected cells and support the B cell response. People who have been both vaccinated and naturally infected may develop a more robust and long-lasting immunity, sometimes referred to as “hybrid immunity.”

Source: https://www.nature.com/articles/s41564-020-00813-8

Author: Prof. Dr. Dirk Devroey - Latest update: 2023-12-11 - Copyright: Clinifacts 2025