https://www.canada.ca/fr/sante-publique/services/rapports-publications/releve-maladies-transmissibles-canada-rmtc/numero-mensuel/2022-48/numero-1-janvier-2022/test-serologique-au-point-intervention-covid-19.html 2022 Canada COVID-19 journal article Serological tests canada community networks serologic tests serologic test, nos Public health registries public health laboratory test, nos laboratories reticulum COVID-19 Serological Testing