A  new study has found that even a mild case of COVID-19 can reportedly leave people with long-lasting protection against the virus. Researchers are now calling previous reports that stated the immunity one had following a coronavirus diagnosis was not long-lived “a misrepresentation of the data.”


In a study that was conducted by Washington University School of Medicine in St. Louis, researchers collected bone marrow samples from 18 of 77 participants who had signed up to give blood samples every three months, starting about a month after the initial infection. The bone marrow samples were collected between seven and eight months after the initial COVID-19 infection. Five of the 18 participants gave a second bone marrow sample about four months later. 

The team compared those samples with the bone marrow collected from 11 people who were never diagnosed with COVID-19. 

While antibody levels in people who had previous COVID-19 infections dropped quickly in the first few months, they did eventually level off and some antibodies were detectable even 11 full months after the infection. 

Researchers also found antibody-producing cells, especially those targeting SARS-CoV-2, in 15 of the bone marrow samples. The cells were also detected in all five of the follow-up samples. 

Researchers said the cells were “quiescent, just sitting in the bone marrow and secreting antibodies.” 

However, researchers said it is not yet clear if those who had more severe COVID-19 infections would have similar long-lasting protection, given that too much inflammation could essentially lead to a defective immune response.

The team of researchers has called for more research to be conducted to replicate the study in people who were diagnosed with moderate and severe COVID-19 infection.