Canada looking at new evidence Pfizer vaccine may work almost as well with just one dose

Deputy chief public health officer Dr. Howard Njoo says data presented by two Canadian doctors in the New England Journal of Medicine this week raises good questions about delaying second doses of the Pfizer-BioNTech vaccine. The evidence suggests the vaccine was almost as effective two weeks after one dose as earlier trials showed it was after two doses and the doctors say with scarce vaccine supplies it may be more beneficial to give more people one dose.