Health & Wellness

When will 2nd vaccine doses be given @ 21-28 days due to very low efficacy of 1st dose against UK and Indian variant?

Deal Expert
Feb 29, 2008
29096 posts
4786 upvotes
Montreal
DealsinThe6ix wrote: Thanks for the link!

But I think England is using the recommended interval of 21 days for Pfizer and 4weeks to 8weeks for Astrazeneca, and these numbers are for vaccine effectivness against hospitalization.

What about after vaccine effectiveness against symptomatic disease after 8weeks or more after 1st dose, which is what Canada is doing, at least for mRNA vaccines?

We know after 1 dose for Pfizer, it's 33% effectiveness against symptomatic disease for delta variant, and 2nd dose 21 days after 1st dose, effectiveness is 88%, but this is not the reality in Canada. The reality is 8weeks or more after 1st dose.

I think we all need clarity for mRNA effectiveness against symptomatic disease 8 weeks or more after 1st dose against this delta variant.
The UK used 12 weeks for both products until recently when they cut to 8 because of Delta.

They have published 12 week data and antibody response.

Here is Quebec's 16 week data if you can read french:

https://mobile.inspq.qc.ca/publications ... eurs-sante
[OP]
Newbie
Feb 26, 2021
88 posts
39 upvotes
Thanks for the Quebec study and clarification on UK's 2nd dose interval. It seems then the UK study will be very much applicable to Canada.

Here's the Google translation for your link to the Quebec study, which at the time was 90% of alpha variant, but good info!

  • Vaccine efficacy (VE) against SARS-CoV-2 infection regardless of its severity and after adjustment for certain variables (week of onset of symptoms or of the test, age, sex, type of facility, type of (employment and health region) was 70.9% 14 or more days after a single dose of vaccine and 86.9% 7 or more days after two doses.
  • VE against symptomatic COVID-19 infection increased to 73.4% after one dose and to 94.2% after 2 doses.
  • The VE against hospitalization was 97.9% after a single dose and no cases were hospitalized after two doses.
  • VE against COVID-19 remained relatively stable during the period between 2 and 16 weeks after the first dose.
  • The VE against COVID-19 was approximately 15% lower for the variants of concern (90% of which are alpha (B1.1.7) variants) than for all other SARS-CoV-2. VE against variants of concern did not appear to decrease over time.
  • In conclusion, a single dose of mRNA vaccine was associated with a three-quarter reduction in the risk of COVID-19 among healthcare workers and a greater than 95% reduction in their risk of hospitalization.
Deal Addict
User avatar
Feb 17, 2015
1152 posts
1524 upvotes
90.00° N, 135.00° W
They said the shipment for pfizer vaccine is mid-week this week. I assume, Wednesday (yesterday).

Hope someone can confirm here if they got pfizer today (GTA Area). I have an appointment in the afternoon and thinking of cancelling in advance if Moderna is still the vaccine of choice.

Thanks.
Deal Expert
User avatar
Oct 5, 2008
17013 posts
12413 upvotes
Toronto
CuriousJack wrote: They said the shipment for pfizer vaccine is mid-week this week. I assume, Wednesday (yesterday).

Hope someone can confirm here if they got pfizer today (GTA Area). I have an appointment in the afternoon and thinking of cancelling in advance if Moderna is still the vaccine of choice.

Thanks.
you've asked this in 5 separate threads.

Why?
Deal Addict
User avatar
Feb 17, 2015
1152 posts
1524 upvotes
90.00° N, 135.00° W
Hahaha. I want to get answers asap. I will be cancelling 2 hours before my appointment if I did not get confirmation. So somebody can get my spot and not just waste it.
Swerny wrote: you've asked this in 5 separate threads.

Why?

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