We are amazed at the spin on the Astra vaccine. This was always designed as a two equal dose trial – 0.5 followed by 0.5 – and this population group has only achieved 62% efficacy (compared to a claim of 95% for the mRNA vaccines).
Now in breach of trial protocol they tell us there’s an improved “90% efficacy” in a small initial 0.25 dose followed by a bigger 0.5 dose, in an unofficial population sub-set which is probably so small as to be statistically insignificant. Moreover, they claim to have stumbled across this better recipe purely by accident, and somewhat embarrassingly claim this sub-set consisted of the volunteers who were systematically but “accidentally” given a smaller than intended dose, as reported here. (The Guardian has more details on this “accident” here.)
So riddle me this: the main dose trial shows only 62% efficacy in healthy adults (almost certainly less in the old and already sick) but a smaller sub-set shows efficacy with a lower dose? Lower doses usually lower side effects but they don’t usually result in higher efficacy. So there’s something bogus going on.
Moreover, if the vaccine really does work better with a smaller first dose then what does that say about the antibody response? Is the immune system producing antibodies to the second dose after a similarly-sized first dose? Is this why counterintuitively it works better on a small first dose? Does the volunteer develop immunity to the second vaccine after a bigger first dose?
If so, at best this is a one shot and one season vaccine.
At worst, if the first full dose does raise antibodies to the second full dose then you have the potential for auto-immune side effects, meaning that the vaccine ultimately inhibits the natural antibody response to the virus which would be disastrous in otherwise healthy adults.
Based on this data, the FDA is unlikely to approve the Astra vaccine (though undoubtedly the UK Government will) as:
* The trial protocol has been violated to data mine a more positive outcome.
* The duration of the efficacy is questionable.
* The overall efficacy is much lower than peers and it likely won’t work at all in the vulnerable (82 year-olds with comorbidities.) The US has mRNA.
* There’s no claim that it prevents virus transmission.
* They will want to monitor possible auto-immune side effects.
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