Can you have different vaccines for each dose?

[BeyondThunderdome]

Obviously the vaccine trials have each been done individually.

But I was wondering, do you think it would be theoretically possible to have different vaccines (say for those who had allergic reactions to their first dose, or if there is a supply chain issue), and get the same level of coverage as you do from two vaccines?

No. They all work differently/ have different components. You absolutely would have to have the same one both times.

No, You would need the same one both times.

Oh I know, I was thinking of the outcome (whether it is T cell or antibody immunity) being the same rather than the method.

So assuming they both work to produce antibodies, if one dose is 45% effective and a separate vaccine also 45% effective (picking random numbers here), could they add together?
Obviously if one produced T cell immunity and the other, antibodies, they couldn't add together then

Someone asked this question in one of those BBC News "ask the experts" segments last week and the answers was technically yes, but in practice not because they are not licensed for being used like that.

They addressed this on the 'how to vaccinate the world' podcast on R4. It was really interesting, and is something yet unknown. If it does work it would be make vaccinating the population so much easier. They didn't say it wasn't possible, just not know yet if it would work.

They’re just about to start trials combining one dose of the Pfizer vaccine with one dose of the Oxford vaccine to see if they’re better combined, as they each work in a slightly different way. So, potentially yes but the research isn’t done yet.

I wonder if there will ever be a single dose?

Thanks, I'll have to find that podcast :)