Like other viruses, coronavirus relies on proteins—the keys that open the doors of human cells. So, to conquer COVID-19, scientists must identify antibodies—the grains of sand that stop the virus from turning its keys in the cellular locks.

To understand the molecular mechanism of coronavirus, Andrés Finzi, associate professor in the Department of Microbiology, Infectiology and Immunology at Université de Montréal and Canada Research Chair in Retroviral Entry at the Centre de recherche du CHUM, designed a new type of serological tests (blood tests) in collaboration with Héma-Québec and the Laboratoire de la santé publique du Québec.

Immunity to COVID-19 increases very rapidly following infection but the number of antibodies begins to drop as early as six weeks after onset.

Professor Finzi and his team conducted the tests and were among the very first to demonstrate that immunity to COVID-19 increases very rapidly following infection but the number of antibodies begins to drop as early as six weeks after onset. In addition, while several antibodies recognize the virus, only some are able to halt it.

Andrés Finzi and Héma-Québec also used the tests to determine the quality of the convalescent plasma (i.e. blood serum from people who have healed from COVID-19) to be transfused to patients infected with coronavirus as part of a clinical study led by Dr. Philippe Bégin at CHU Sainte-Justine. The experts believe that it may be possible to transfer the protective antibodies of people who have overcome the disease to patients in the early stages of COVID-19 and limit the severity of their symptoms. The clinical trial is currently underway in Québec as Professor Finzi works to uncover optimal beneficial antibodies in the hopes of concocting a cocktail that could eventually serve as the basis of a new form of treatment.