Australian scientists have described changes in immunity levels up to four months after infection with COVID-19, finding that while antibody levels decline dramatically in the first one to two months, the decline then slows down. considerably.
The results suggest that protective COVID-19 vaccines should ideally generate stronger antibody responses than natural infection.
The research team, including Dr Jennifer Juno of the University of Melbourne, a principal investigator at the Peter Doherty Institute for Infection and Immunity (Doherty Institute), studied how the immune system, particularly B and T cells , reacts to COVID-19 advanced proteins.
The spike protein allows SARS-CoV-2 to attach and enter cells in humans and is crucial for inducing neutralizing antibodies to protect against reinfection.
B cells are responsible for producing the antibodies that recognize SARS-CoV-2, while T cells play an important role in developing the B cell response.
Dr Juno said that one of their striking observations was that over the course of the four months they were following patients, the number of B cells recognizing the spike protein actually increased in almost everyone, regardless of the severity of the disease. their illness.
“It’s interesting because our work and other recent studies suggest that these B cells continue to accumulate and potentially evolve over time. This should be useful for protection in the event of another exposure in the sense that these “memory” cells should be able to be reactivated, ”Dr. Juno said.
“While we still don’t know how many antibodies you actually need to be protected, whether from a vaccine or from natural infections, recent results from Phase 3 vaccine trials should soon allow us to understand how many time natural immunity should last.
“Moreover, it remains to be understood whether these changes in B cell memory can help the immune system recognize and protect against the new variants of SARS-CoV-2 that are emerging today.”
Dr Juno said recent data on major vaccines shows that they cause at least double the levels of antibodies as a natural infection, which is very encouraging.
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Adam K. Wheatley et al. Evolution of immune responses to SARS-CoV-2 in mild to moderate COVID-19, Nature’s communications (2021). DOI: 10.1038 / s41467-021-21444-5
Provided by Doherty Institute for Infection and Immunity
Quote: What Happens to Immunity Levels After COVID-19 Infection? (2021, February 22) retrieved February 22, 2021 from https://medicalxpress.com/news/2021-02-immunity-covid-infection.html
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