Recovered from Covid-19? Your immune system may fight coronavirus variants

Instead of producing antibodies all the time, the immune system creates memory B cells that recognise the coronavirus, and quickly unleash a new round of antibodies.

By: Satata Karmakar | | Updated: January 26, 2021 10:23 am

Immune system of recovered coronavirus patients can fight the variants

Have you recently recovered from the novel coronavirus? Are you worried about getting re-infected by the new strain? There’s a good news for you then. People who recover from COVID-19 are protected against the novel coronavirus for at least six months, and likely much longer. Yes, you read it right. Also Read - Woman dies hours after taking second COVID-19 vaccine dose in MP

A new study has revealed that the immune system evolves long after the infection and may block even mutant forms of the virus such as the South African variant. Also Read - New study suggests rats, water buffalo and mountain gorillas can spread COVID-19 virus

Published in the journal Nature, the researchers noted that antibodies are produced by immune cells that keep evolving, apparently due to continued exposure to remnants of the virus hidden in the gut tissue. Also Read - COVID-19 Unlock: How to ensure students and teachers are safe amid schools reopening

Speaking to the media, the scientists stressed that the study provides the “strongest evidence yet” that the immune system “remembers” the virus and, remarkably, continues to improve the quality of antibodies even after the infection has waned.

How Does A Recovered Patient’s Body Prevent Coronavirus Re-Infection

When a new strain tries to attack a coronavirus recovered patient, the responses of the body’s immunity becomes faster and more effective, thus, preventing reinfection.

The researchers said that the type of immune response they found during the study, could potentially provide protection for quite some time, by enabling the body to mount a rapid and effective response to the virus upon re-exposure.

While antibodies against the coronavirus linger in the blood plasma for several weeks or months, earlier studies have shown that their levels significantly drop with time.

No! Not The Antibodies, Its Memory B Cells That Keeps You Protected

Instead of producing antibodies all the time, the immune system creates memory B cells that recognise the coronavirus, and quickly unleash a new round of antibodies when they encounter it a second time.

How are these memory B cells being created? According to the scientists, the novel coronavirus replicates in the cells of the lungs, upper throat, and small intestine, that residual viral particles hiding within these tissues could be driving the evolution of memory B cells.

Coronavirus Antibodies May Get Reduced By Five-Fold

In the current study, the scientists studied the antibody responses of 87 individuals at two timepoints — one month after infection, and then again six months later.

Although antibodies were still detectable by the six-month point, their numbers had markedly decreased, with lab experiments revealing that the ability of the participants’ plasma samples to neutralise the virus was reduced by five-fold.

In contrast, the researchers found that the patients’ memory B cells — specifically those that produce antibodies against the coronavirus — did not decline in number. These cells also slightly increased in some cases, the study noted.

Memory B Cells Also Goes Through Mutations

The scientists also discovered that the memory B cells had gone through numerous rounds of mutation even after the infection resolved.

As a result, the antibodies they produced were much more effective than the originals, the study noted.

According to the researchers, these antibodies were better able to latch on tightly to the virus and could recognize even mutated versions of it.

“The overall numbers of memory B cells that produced antibodies attacking the Achilles’ heel of the virus, known as the receptor-binding domain, stayed the same,” said Christian Gaebler, another co-author of the study.

“That’s good news because those are the ones that you need if you encounter the virus again,” Gaebler said.

(With inputs from IANS)

Published : January 25, 2021 9:18 am | Updated:January 26, 2021 10:23 am

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