[ Sign up for our Health IQ newsletter for the latest coronavirus updates ]In a non-peer-reviewed study posted on the bioRxiv prepublication server, Finzi’s team evaluated the capacity to neutralize plasma — the liquid component of blood containing antibodies — one, two, three and six weeks after the onset of symptoms of the disease.The team used plasma samples from 108 patients, healthy, infected or convalescent, provided by Héma-Québec and the Laboratoire de santé publique du Québec.The researchers found that after three weeks, more than 90 per cent of those infected had antibodies that recognize one of the signatures of SARS-CoV-2, the glycoprotein S.