The UK authorized the AstraZeneca-Oxford COVID-19 vaccine. Monumental!
But the BIGGER news centers upon the UK's changes to vaccine schedules. They will now allow people to delay their 2nd doses for up to 12 weeks.
Here's why that might be a gamble...
gov.uk/government/new…
But the BIGGER news centers upon the UK's changes to vaccine schedules. They will now allow people to delay their 2nd doses for up to 12 weeks.
Here's why that might be a gamble...
gov.uk/government/new…
1. UK's announcement came with some new data about the AstraZeneca-Oxford vaccine, which are summarized in this regulatory document:
assets.publishing.service.gov.uk/government/upl…
Chief among them is that a single-dose showed 73% efficacy against COVID-19 after nearly a month...
assets.publishing.service.gov.uk/government/upl…
Chief among them is that a single-dose showed 73% efficacy against COVID-19 after nearly a month...
...hence why the Joint Committee on Vaccination and
Immunisation says "the second dose of the AstraZeneca vaccine may be given between 4 to 12 weeks following the first dose."
That's fine and dandy. The weird part centers around the UK's decision with the Pfizer vaccine...
Immunisation says "the second dose of the AstraZeneca vaccine may be given between 4 to 12 weeks following the first dose."
That's fine and dandy. The weird part centers around the UK's decision with the Pfizer vaccine...
2. UK regulators say, based on unpublished data, that the 2nd dose of Pfizer-BioNTech vaccine can also now be given *between 3 to 12 weeks* after the 1st dose.
The original rule, which was based on the clinical trial, calls for a 2nd dose precisely 3 weeks after the 1st dose.
The original rule, which was based on the clinical trial, calls for a 2nd dose precisely 3 weeks after the 1st dose.
Why this doesn't make sense:
Based on publicly available data on the clinical trial, the Pfizer-BioNTech vaccine showed only 52% efficacy after the first dose.
In other words, only half of the takers were protected after a single dose.
bmj.com/content/371/bm…
Based on publicly available data on the clinical trial, the Pfizer-BioNTech vaccine showed only 52% efficacy after the first dose.
In other words, only half of the takers were protected after a single dose.
bmj.com/content/371/bm…
Compare that against protecting nine of every 10 people (94%) with two doses the Pfizer-BioNTech.
Sure, a single dose allows them to double the recipients, but they'd be halving the number of people who develop protection (or thereabouts)...so where's the gain?
Sure, a single dose allows them to double the recipients, but they'd be halving the number of people who develop protection (or thereabouts)...so where's the gain?
Also, it's unclear how durable the Pfizer-BioNTech immunity is after a single dose. To recap...
AstraZeneca second dose after 4-12 weeks: 👍
Pfizer second after 3-12 weeks:
AstraZeneca second dose after 4-12 weeks: 👍
Pfizer second after 3-12 weeks:
Sources
MHRA regulatory docs here: gov.uk/government/pub…
This one has the AstraZeneca efficacy data: assets.publishing.service.gov.uk/government/upl…
JCVI advice on scheduling: gov.uk/government/pub…
Press conference:
Presser slides: gov.uk/government/pub…
MHRA regulatory docs here: gov.uk/government/pub…
This one has the AstraZeneca efficacy data: assets.publishing.service.gov.uk/government/upl…
JCVI advice on scheduling: gov.uk/government/pub…
Press conference:
Presser slides: gov.uk/government/pub…
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