RT Journal Article SR Electronic T1 Nirmatrelvir-ritonavir for COVID-19 JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E218 OP E218 DO 10.1503/cmaj.220081 VO 194 IS 6 A1 Emily G McDonald A1 Todd C Lee YR 2022 UL http://www.cmaj.ca/content/194/6/E218.abstract