Study reveals most people who recovered from Covid & were later immunized, will not need boosters

May 30: A recent study, titled, SARS-COV-2 infection induces long-lived bone marrow plasma cells in human beings, suggests that immunity could last for over a year and improves over time, especially after vaccination. It added that most people who recovered from Covid and were later immunized, will not need booster doses.

One of the studies claims that the cells that retain a memory of the virus persist in the bone marrow and may produce anti-bodies whenever needed. As per reports, in another study, which is also under review for publication, these so-called memory B cells continue to mature and strengthen for atleast 12 months after the initial infection.

Michel Nussenzweig, an Immunologist at Rockefeller University said, “These memory B cells produced in response to infection with SARS-COV-2 are enhanced with vaccination and are so potent that they thwart even variants of the virus, negating the need for boosters.”

As a part of the experiment, blood from 77 people infected with coronavirus was analysed at three-month intervals. Antibody levels in these individuals dropped rapidly four months after infection and continued to decline, though memory B cells remained quiescent in the bone marrow.

In one study, bone marrow samples from 19 people were obtained roughly 7 months after they had been infected. 15 people had detachable memory B cells but 4 did not. This suggests that some people might carry very few of the cells or none at all.

In the second study, researchers analysed blood from 63 people who had recovered from Covid-19 to study how memory B cells mature. The so-called neutralising anti-bodies remained unchanged between 6 and 12 months. As memory B cells continued to evolve, the anti-bodies they produced developed the ability to neutralise an even broader group of variants.

A year after infection, neutralising activity in the participants who had not been vaccinated was lower against all forms of the virus. Those who were vaccinated will continue to have higher protection against the emerging variants. This suggests that those who were never infected and did not produce a robust immune response may need booster shots.

Inputs Credit: Inshorts