Okay one more thread before bed! Lots of Qs asking "what IS VITT?" Before I get to that, if you'd like an AWESOME metaphor about vaccine choice, please read my buddy @DrKateJMiller's, then read on for some FACTS about VITT clots caused by AZ and J&J... https://twitter.com/DrKateJMiller/status/1391173201623924737?s=20

@COVIDSciOntario has published an evidence based brief on VITT (which includes a lay summary). All science, no spin. (Seriously, no spin.) @heysciencesam has helped us break the VITT facts down into tasty evidence bites. https://covid19-sciencetable.ca/sciencebrief/vaccine-induced-immune-thrombotic-thrombocytopenia-vitt-following-adenovirus-vector-covid-19-vaccination/

These are the facts. 4-28 day window for symptoms to start (typical immune reaction... just like autoimmune HIT for the #hemetwitter nerds). Those incidence figures are referenced in the brief. https://covid19-sciencetable.ca/sciencebrief/vaccine-induced-immune-thrombotic-thrombocytopenia-vitt-following-adenovirus-vector-covid-19-vaccination/

Can we predict who's likely to get VITT after an adenoviral vector COVID-19 vaccine? Unfortunately not well (or at least, not yet). We don't believe it's common in folks with lots of "classical" risk factors for blood clots.

Pregnant people likely aren't at increased risk of VITT - but NACI recommended they get mRNA vaccines because VITT is more challenging to treat if pregnant. Of course, like ANY vaccine choice, one must weigh risk of waiting for an mRNA vaccine with risk of VITT.

We think that the people with HIT and people with CSVT + low plts shouldn't get adenoviral vector vaccines - they MAY be at increased risk (no clear evidence) and may do worse. Women and younger people MAY be at slightly higher risk, but the jury is out.

I know this info may be scary. But even when science is alarming - it's still true. I would rather you know about VITT, so if you decide to get AZ or J&J, you know what to look for. Medical paternalism is an expedient but always bad choice. Demand transparency. Be empowered.

I empathize with the anxiety this evolving science brings. Please practice self care.

I am *very* alarmed at some of the rhetoric I've read around VITT. I implore you - seek trusted sources when you research this condition (not all MDs know about blood clots, just as not all MDs know about viruses or vaccines). Look for voices that are honest and kind.

And know that many of us are trying VERY hard to ensure VITT is on the radar of every HCP in Canada. As @heysciencesam says: be aware, not scared. Trust me when I say: we are getting through this pandemic, not without disappointments & grief... but we are getting through it.