Researchers from Université de Montréal, Dr Daniel Kaufmann and Dr Andres Finzi, in collaboration with researchers from New York University, are confirming the presence of a long-lasting immune response to the novel coronavirus SARS-CoV-2, the virus that causes COVID-19. This publication is part of their research funded by the Government of Canada through its COVID-19 Immunity Task Force and the Canadian Institutes for Health Research.
Although the researchers confirm previous work showing that the antibodies capable to block new infections eventually decline over time, they reveal that the cells that produce these antibodies (known as SARS-CoV-2-specific B cells) remain detectable for up to eight (8) months. Also, after the initial infection is controlled, B cells evolve into memory B cells. As their names suggest, these cells remember the virus they just fought, and are capable of fighting potential new infections faster and better than the original cells. Remarkably, the investigators detected these SARS-CoV-2-specific memory B cells in all of the recovered COVID-19 patients tested.
Another important function of antibodies is to label cells that have been infected so that specialized immune cells can find and destroy the infected cells. This kills the virus they harvest and contains the spread of the infection. Using an assay developed by their team, the presence of antibodies capable to target SARS-CoV-2 infected cells for destruction was detected also for up to eight (8) months, in 85% of the recovered COVID-19 patients.
A functional and long-lasting immune response to SARS-CoV-2 is critical to prevent re-infections, enable herd immunity and predict vaccine effectiveness. In summary, their results on the persistence of SARS-CoV-2-specific memory B cells after natural infection provides optimism towards achieving long-term protection through vaccination.
Anand SP, Prévost J, Nayrac M, Beaudoin-Bussières G, Benlarbi M, Gasser R, Brassard N, Laumaea A, Gong SY, Bourassa C, Brunet-Ratnasingham E, Medjahed E, Gendron-Lepage G, Goyette G, Gokool L, Morrisseau C, Bégin P, Martel-Laferrière V, Tremblay C, Richard J, Bazin R, Duerr R, Kaufmann D, Finzi A. Longitudinal analysis of humoral immunity against SARS-CoV-2 Spike in convalescent individuals up to 8 months post-symptom onset. Cell Rep Med. 2021 May 4. doi: 10.1016/j.xcrm.2021.100290.