Coronavirus: preexisting immunity in half people never infected

Published by Elodie D. · Published on 3 August 2020 at 14h14
Half the population is said to be already protected against coronavirus thanks to specific lymphocytes T. This is what a study published in the famous scientific Nature magazine finds.

A team of scientists from the Singapore Duke-NUS Medical School focused their research on lymphocytes T targeting SARS-COV-2 coronavirus. And results published in Nature are “encouraging”. As a matter of fact, they found the eradication of the virus by production of lymphocytes T gives a more “robust and viable” cell immunity than the one caused by antibodies that quickly disappeared.

These lymphocytes T especially fighting against SARS-COV-2 are found in former SARS (Severe Acute Respiratory Syndrome) patients, seventeen years after their recovery. And especially, and against all odds, they have bee found in over 50% health people who has never been infected by SARS-CoV-2 or SARS. These lymphocytes would have been produced after a reaction to an unknown animal coronavirus, giving cross immunity.

The study does not show if the presence of these lymphocytes T is enough to lead to total recovery of Covid-19, but this immune response “probably” alleviates the infection and could lead to herd immunity quicker.

According to Pr. Benjamin Terrier from Paris Hôpital Cochin, interviewed by Le Monde, this result “lets us think that patients who developed Covid-19 can – like patients formerly infected by SARS – develop a long-time specific SARS-CoV-2 memory cell immunity”.

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