The immune system’s response to coronavirus reinfection is faster, stronger, and could take years (study) – Coronavirus

Scientists at Rockefeller University in New York have found that not only does the immune system remember the virus, but it also improves the quality of protective antibodies after an infection, allowing the body to launch a quick and strong attack if it becomes infected with the virus again.

“This is great news,” said Michel Nussenzweig, who heads Rockerefeller’s department of molecular immunology. He adds that the study indicates that humans could produce a rapid antibody response and resist re-infection in a large number of cases.

It’s unclear how long the immune system’s memory can last, but Nussenzweig believes it can provide protection for many years. The finding may explain why the number of certified reinfections is so small.

When a person becomes infected with the coronavirus, the immune system launches a multilevel attack. One of the forms of protection comes from T cells, which seek out and destroy infected cells and thereby prevent the spread of the virus. A second layer involves B cells, which release antibodies into the bloodstream and prevent viruses from invading the cells.

After healing, the immune system retains the memory of the virus through so-called memory T cells and memory B cells.

Several studies have shown that the first wave of antibodies diminishes after a few months, which has raised concerns that people may quickly lose their immunity. In a study of 87 coronavirus-infected patients, US researchers confirmed this drop in antibody levels to about a fifth of the maximum level after about six months, but I don’t think it matters much.

The scientists looked at the memory of the immune system and found that six months after infection, the antibodies produced by memory B cells evolved to become stronger. These improved antibodies can be released the day after reinfection, instead of about two weeks, as in primary infections.

The researchers also observed small amounts of coronaviruses, or protein fragments of inactive viral particles, in the gut of patients that apparently help maintain the memory of the immune system. These remnants of the virus are believed to be harmless.

“We don’t know how long the protection will last, but it could be a long time. It could take years.”

The study was not subject to the review procedure.

Charles Bangham, a professor of immunology at Imperial College London who was not involved in the study, says the research indicates “a good possibility that if you are exposed to the virus again, a faster immune response will develop.”

Arne Akbar, professor of immunology at University College London, said: “This is good news for anyone infected with the coronavirus.” According to him, the immune system is like an army that retreats as the threat disappears, but is ready for a future invasion.