From some reason, this @BusinessInsider article from Feb 23rd is making the rounds today on social media: https://www.businessinsider.com/new-data-calls-into-question-delaying-2nd-coronavirus-vaccine-dose-2021-2
The sensationalist headline "Scotland's vaccine rollout suggests delaying the 2nd #COVID19 shot is a bad idea" requires some serious nuance.
1/6
The sensationalist headline "Scotland's vaccine rollout suggests delaying the 2nd #COVID19 shot is a bad idea" requires some serious nuance.
1/6
The news article references a Feb 19th pre-print: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3789264
This means that the study was neither peer-reviewed nor finalized when posted.
The pre-print reported a combined 58% vaccine effectiveness for #Pfizer and #AstraZeneca starting 42 days after 1 dose.
2/6
This means that the study was neither peer-reviewed nor finalized when posted.
The pre-print reported a combined 58% vaccine effectiveness for #Pfizer and #AstraZeneca starting 42 days after 1 dose.
2/6
This pre-print went on to be peer-reviewed and published last week in @TheLancet: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00677-2/fulltext
@TheLancet study reported a combined 74% vaccine effectiveness for #Pfizer and #AstraZeneca starting 42 days after the first dose (77% for the #Pfizer vaccine alone).
3/6
@TheLancet study reported a combined 74% vaccine effectiveness for #Pfizer and #AstraZeneca starting 42 days after the first dose (77% for the #Pfizer vaccine alone).
3/6
The U.K. has seen remarkable control of the pandemic with a strategy maximizing first vaccine doses for as many as possible.
Modelling work led by @BeateSander shows that such an extended dose interval strategy will also save more lives in Canada: https://www.medrxiv.org/content/10.1101/2021.04.07.21255094v1
4/6
Modelling work led by @BeateSander shows that such an extended dose interval strategy will also save more lives in Canada: https://www.medrxiv.org/content/10.1101/2021.04.07.21255094v1
4/6
Sharing this article without proper context and fear-mongering statements are harmful.
Of course it is important to continuously evaluate and update Canada's vaccine strategy as new data emerges— @cdavidnaylor and @BogochIsaac have written about this: https://www.theglobeandmail.com/opinion/article-when-it-comes-to-vaccine-delivery-we-need-a-very-canadian-compromise/
5/6
Of course it is important to continuously evaluate and update Canada's vaccine strategy as new data emerges— @cdavidnaylor and @BogochIsaac have written about this: https://www.theglobeandmail.com/opinion/article-when-it-comes-to-vaccine-delivery-we-need-a-very-canadian-compromise/
5/6
This includes determining which populations:
1. Require two doses following the same interval as the clinical trials
2. Should be prioritized for earlier second doses
#NACI has compiled and reviewed the existing evidence on extended dose intervals: https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/extended-dose-intervals-covid-19-vaccines-early-rollout-population-protection.html
6/6
1. Require two doses following the same interval as the clinical trials
2. Should be prioritized for earlier second doses
#NACI has compiled and reviewed the existing evidence on extended dose intervals: https://www.canada.ca/en/public-health/services/immunization/national-advisory-committee-on-immunization-naci/extended-dose-intervals-covid-19-vaccines-early-rollout-population-protection.html
6/6