Cyberyeti, on 2022-March-11, 05:52, said:
https://www.cam.ac.u...avirus-vaccines
My understanding when this was explained on the radio was they were targeting bits of the virus that were less likely to mutate to try to make a vaccine that would work against future variants.
I think that's another issue.
Both ideas are possible.
I'm not a virologist but it would obviously be a good thing if they could find an antigen on the virus that was static and could not change without losing virulence.
I do have experience in making antibodies. It's very hard.
There are so many problems here.
1) there might be a protein (called the antigen - antigens can have multiple epitopes which are the individual sites antibodies bind to) that is unique and doesn't change but is not on the outside of the virus.
The protein must be exposed to the host to be an 'epitope' if it isn't it's called a 'cryptotope' (or cryptope) this means that antibodies made against it can't see it in the virus and therefore don't work. This is a really common problem when making antibodies.
2) some proteins are incredibly hard to make antibodies to - some are impossible - don't get me started.
3) even if you find a protein that is a good candidate it has to be really really antigenic to be useful for immunising a whole population because it needs to make >99.99% of subjects immune to be effective. Most of the time when making antibodies in the lab. a 2/3 success rate is acceptable. This will not cut it in immunisation programs.
4) Not all antibodies are the same. You have to have an antigen that provokes a really good response resulting in neutralising antibodies in nearly everyone.
I can see why they went for the spike protein. It sits on the outside and looks like the bristles of a brush. Clearly the most likely target.
Another approach is to make a drug that blocks the enzyme that the virus uses to turn the cellular machinery into a virus factory - like molnuprivar which blocks the RNA dependent RNA polymerase (RdRp). Of course this is not good as a prophylactic and can't replace vaccination.