Yet another vaccine question

[Jontie]

Does anyone know if the first and second dose of the Oxford astrazeneca vaccine are identical in terms of chemical composition and quantity?

I've read that this is the case with the pfeiser and moderna vaccines but I can't find the info for the Oxford one.

I'm interested because I'll be on 15mg pred when I have the first dose, and hopefully 12.5 or less when I have the second. I'm hoping that if I don't get much immune response from the first, at least I'll stand a better chance of benefitting from the second. Thanks.

[PMRpro Ambassador]

As far as I know all boosters are identical to the first injection. They did discuss and approve the use of a DIFFERENT vaccine if there were supply problems but that is only for emergencies. The whole purpose of a booster is to increase the level of immunity and there are some vaccines (not Covid ones) that require the booster to achieve full immunity.

[piglette]

Currently they are although they are working on a new vaccine to work better with the mutations. This may be ready in the autumn. .

[Jontie]

I did read a paper, in Nature I think, which reported positive results of administering a lower first dose followed by a "full" second dose. However I think it was a small sample size, and I assume this practice has not been adopted with the current vaccine roll out.