🧵Let me try and convert the NACI guidance on the Astra Zeneca #vaccine to something understandable. I took the worst case of 1 blood clot (VITT) case per 100,000 and converted the risk categories to est'd weekly cases per 100K ranges. The green cells have positive benefit.⤵️
2. The numbers in each cell are the benefit to harm ratio, eg a 40-49 year old in a region with a weekly case rate of 100 would fall into the "8.64" green cell. That person would have over 8x the benefit of an early AZ vaccination compared to waiting for a Pfizer or Moderna shot.
3. For example, using the upper left hand column below, all the regions in Ontario above Windsor would fall into that category right now and taking an Astra Zeneca now would give you an estimated 8x benefit over waiting.
4. One more example, say you are 57 and you live in Parry Sound. The North Bay Parry Sound region has a weekly case rate per 100,000 population of 6 right now. The benefit ratio is now .60 and is coloured red. That means that based on the assumptions NACI is using for the chances
5. ... of getting a "VITT" blood clot and getting admitted to ICU, the time expected to wait for an MRNA vaccine, and your region's low risk level, you are better off waiting for an mRNA vaccine and holding off getting an Astra Zeneca shot.
6. Many parts of Canada have high enough rates that getting an Astra Zeneca vaccine is smart based on the NACI guidance but if the age cutoff is lowered below 40, having this guidance will become increasingly important.
Here's the full report:
https://www.canada.ca/content/dam/phac-aspc/documents/services/immunization/national-advisory-committee-on-immunization-naci/recommendations-use-covid-19-vaccines/recommendations-use-covid-19-vaccines-en.pdf
7. I chose the 1 in 100,000 blood clot risk. That may turn out to be too pessimistic but I wanted to err on the side of caution. NACI has other tables using different assumptions you can check out if you like. Now you have an extra reason to keep an eye on "weekly cases per 100K"
9/ If you have questions specific to your risks or health, it's best to consult a medical professional and as more Astra Zeneca arrives, you should stay tuned to updated guidance and cutoffs for your province.
You can follow @Billius27.
Tip: mention @twtextapp on a Twitter thread with the keyword “unroll” to get a link to it.

Latest Threads Unrolled: