Immune system ‘remembers’ coronavirus for at least 6 months: study

People may be able to fight off reinfection for at least six months after recovering from COVID-19 with cells able to “remember” the virus, according to a study released Monday.

Researchers in the United States and Switzerland have studied dozens of people who have recovered from COVID-19 and found that while their antibodies may wear off over time, they maintain specific memory B cell levels.

These cells can remember the pathogen and can, if faced with reinfection, trigger the immune system to restart the production of anti-virus antibodies.

“Memory responses are responsible for protection against reinfection and are essential for effective vaccination,” concluded the study published in the journal Nature.

“The observation that B cell memory responses do not break down after 6.2 months, but continue to evolve, strongly suggests that people infected with SARS-CoV-2 may respond quickly and effectively to the virus when re-exposure. “

The authors evaluated 87 people with a confirmed diagnosis of COVID-19 just over a month and six months after infection.

Although they found that the activity of virus-neutralizing antibodies decreased over time, the number of memory B cells remained unchanged.

The researchers said their study indicated that the memory B cell response to the coronavirus changes over the course of six months after infection in the presence of residual viral proteins in the body, allowing the cells to make stronger antibodies.

How long can people fight off reinfection with the novel coronavirus and what immune process is involved are critical in predicting the dynamics of the pandemic.

Previous research has raised concerns that it shows that neutralizing antibodies can decrease quickly after infection with SARS-CoV-2.

But more recent studies have highlighted the role of other parts of the immune system in long-term immunity.

An article published in the journal Science This month, almost all of the major parts of the immune system that can learn to recognize and repel a new pathogen could continue to respond to the virus for at least eight months.

This included memory B cells specific to the protein spikes, which the researchers found actually increased in the blood six months after infection.

The article was based on analyzes of blood samples from 188 patients with COVID-19.

© 2021 AFP