Making It Up As They Go Along

[Sunk]

Public Health England approves mixing doses of different covid vaccines.

https://www.theguardian.com/world/2021/jan/02/england-health-officials-defend-contingency-plan-to-mix-covid-vaccines

// Virologist Prof John Moore from Cornell University in the US, who said “there are no data on this idea whatsoever” and that British officials “seem to have abandoned science completely now and are just trying to guess their way out of a mess”. //

// Dr Mary Ramsay, Public Health England's head of immunisations, said: "We do not recommend mixing the Covid-19 vaccines - if your first dose is the Pfizer vaccine you should not be given the AstraZeneca vaccine for your second dose and vice versa."
Dr Ramsay added that on the "extremely rare occasions" where the same vaccine is unavailable... it is "better to give a second dose of another vaccine than not at all". //

Is this bonkers?

[woofgang]

Sqad "woofy.....I hopened my message would have been quite clear.
You gather the evidence, formulate a plan, implement that plan and only modify when there are clear indications that your plan can be improved.
Nothing that I have seen would be of any advantage other than to complicate an already difficult task."

The advantage is that you can protect more people more quickly by lengthening the gap between doses. The advice about mixing vaccines has only been needed since there are two vaccines being given. I would say the the former is a clear indication that the plan can be improved and the latter a necessary clarification now there are two vaccines being distributed.

[Sqad]

woofy....that i understand but it will confuse many folks so soon after instigating the present policy.
Not good.

[dannyk13]

Surely it is common sense that you do not mix two vaccines which probably have different formulae.

[bhg481]

I'm not sure that's a valid argument, danny. If each vaccine has a 90% chance of working with a set of people it's possible that giving a mixed dose could catch more people. ie, if you are one of the 10% that vaccine A doesn't work for but vaccine B does (and there's no way of knowing in advance) then giving one dose of each might give you some sort of protection.

[woofgang]

danny I see it as maybe an advantage....like taking paracetamol and ibuprofen.

Sqad what is there to be confused about?

[teacake44]

Would you like the covid cocktail sir, manages special, or the bog standard one. :0)))

[jno]

Sunk, I'm not sure "the other one" means "the wrong one". I'm not an epidemiologist, but if as Moore says there are no data on mix and match, then presumably nobody's stood up and said "You can't do that, it's dangerous."

No wonder really, as it's only a week or so since more than one vaccine has been available, so there's been little scope for trialling it. No doubt it will become more complicated as more come on line.

It may be as woofgang has suggested that any two would be usable together, like ibuprofen and paracetamol. Then again, maybe it would be like bleach and vinegar, a very bad idea.

But at the moment there don't seem to be any grounds to rule it out; the current position is just "We don't know".