Thread by @DrJeffKwong

With this week’s delayed Pfizer vaccine shipments, I’m concerned about people delaying dose 2 because they are being offered Moderna vaccine. The last thing we want is any loss of momentum in our flourishing vaccine roll-out. Our analyses using @ICESOntario data show… 1/n

@ICESOntario …that 2 doses of Moderna are just as good as 2 doses of Pfizer (black lines), and that 1 dose of Moderna is slightly better than 1 dose of Pfizer in preventing infections (grey lines). A: VE against symptomatic infection B: VE against hospitalization or death. @ICESOntario 2/n

@ICESOntario For details, please see our pre-print: medrxiv.org/content/10.110… We have since done further analyses adding more data, and confirmed this - indeed, an even greater difference against infection after 1 dose (78% vs. 61%) and similar after 2 doses 3/n

@ICESOntario No reason to think that Pfizer for dose 1 + Moderna for dose 2 would be any worse than 2 doses of Pfizer. So if you got Pfizer for dose 1 and are being offered Moderna for dose 2, rest assured that you are doing the right thing by getting it (and not waiting for Pfizer). 4/4

@ICESOntario Bonus tweet: We are working on vaccine-specific VE estimates against VOCs. So far we are seeing good VE for all 3 vaccines against infections & severe outcomes caused by all variants (Alpha/Beta/Gamma/Delta). Hoping to get our results out ASAP.