"This is a strength of the RNA platform; it’s relatively easy to edit the sequence and generate a new vaccine that responds to mutations in the virus." Can you perhaps say: is it easier to update the genetic material in an mRNA vaccine, vs. an adenovirus-carrier vaccine like the AstraZeneca one now in use in other countries[1] (and others from Russia and China)? In either case you're using well-known techniques to create a nucleic acid sequence and then putting it in some kind of carrier or coating that gets it inside mammalian cells.
Would it be harder for Novavax (whose vaccine is the spike protein, created outside the body in moth cell cultures) to create a strain of moth cells that pump out a slightly different protein? (Because I nitpick myself: Novavax's vaccine is spike proteins attached to a stabilizer that isn't defined clearly in press coverage and is probably proprietary, and accompanied by adjuvant.)
I think really it boils down to the fact that protein synthesis is slower and relies on recombinant genetics and bioreactors to be conducted at scale. RNA synthesis is a chemical process that doesn't need to be redesigned every time the molecule to be synthesized needs to be modified.
Protein synthesis is not this way. While systems like the baculovirus expression platform allow for protein synthesis in a more predictable way than older systems, it is still a complex process involving living cells. There are serious process development investments that have to be made when a change is needed. Proteins just don't synthesize consistently, even with small changes. You really never know what's going to happen when you embark on a new protein synthesis project. It's full of surprises.
RNA synthesis can be done by a chemical process, and is more predictable. I'm sure it has its quirks too, but it's not as finicky.
So in general, if you're making some kind of macrostructure like a protein or a viral vector that involves tissue culture growth, it's going to be harder to retool your process than if you're doing chemical synthesis to make a different RNA sequence.
You knew I'd comment, right?
"This is a strength of the RNA platform; it’s relatively easy to edit the sequence and generate a new vaccine that responds to mutations in the virus." Can you perhaps say: is it easier to update the genetic material in an mRNA vaccine, vs. an adenovirus-carrier vaccine like the AstraZeneca one now in use in other countries[1] (and others from Russia and China)? In either case you're using well-known techniques to create a nucleic acid sequence and then putting it in some kind of carrier or coating that gets it inside mammalian cells.
Would it be harder for Novavax (whose vaccine is the spike protein, created outside the body in moth cell cultures) to create a strain of moth cells that pump out a slightly different protein? (Because I nitpick myself: Novavax's vaccine is spike proteins attached to a stabilizer that isn't defined clearly in press coverage and is probably proprietary, and accompanied by adjuvant.)
Of course I knew you'd comment :)
I think really it boils down to the fact that protein synthesis is slower and relies on recombinant genetics and bioreactors to be conducted at scale. RNA synthesis is a chemical process that doesn't need to be redesigned every time the molecule to be synthesized needs to be modified.
Protein synthesis is not this way. While systems like the baculovirus expression platform allow for protein synthesis in a more predictable way than older systems, it is still a complex process involving living cells. There are serious process development investments that have to be made when a change is needed. Proteins just don't synthesize consistently, even with small changes. You really never know what's going to happen when you embark on a new protein synthesis project. It's full of surprises.
RNA synthesis can be done by a chemical process, and is more predictable. I'm sure it has its quirks too, but it's not as finicky.
So in general, if you're making some kind of macrostructure like a protein or a viral vector that involves tissue culture growth, it's going to be harder to retool your process than if you're doing chemical synthesis to make a different RNA sequence.
[1]Footnote for any non-US readers: I happen to know that both John and myself live in the United States of America.