Protein origin shouldn’t matter, but mRNAs are not yet proteins. So for mRNA vaccines, they still need a lipid coating for delivery that evades the immune system but will still fuse with cell membranes.
(Normal cell-to-bubble-to-cell delivery involves mostly protein-based tagging and anchoring, and viruses often imitate parts of this process (this is much of what coronavirus spike-proteins are doing, for instance). But if you are using variants of tags that appear unfamiliar to the immune system, you can easily get an immune reaction against them. I’m not precisely sure how these companies have solved this problem, whether it’s by using protein-tagging some entirely-lipid-based solution, or what.)
They might not need to be targeting particular cell-types very heavily, it’s true. But they still need to be targeting for delivery to cells-in-general.
To me the successful CureVac phase I trial for Rabies suggests that they do have a solution for the general targeting.
Given that Moderna is already doing their human trials this month and Biontic next month it seems they also have the problem of delievery to cells-in-general solved.
Protein origin shouldn’t matter, but mRNAs are not yet proteins. So for mRNA vaccines, they still need a lipid coating for delivery that evades the immune system but will still fuse with cell membranes.
(Normal cell-to-bubble-to-cell delivery involves mostly protein-based tagging and anchoring, and viruses often imitate parts of this process (this is much of what coronavirus spike-proteins are doing, for instance). But if you are using variants of tags that appear unfamiliar to the immune system, you can easily get an immune reaction against them. I’m not precisely sure how these companies have solved this problem, whether it’s by using protein-tagging some entirely-lipid-based solution, or what.)
They might not need to be targeting particular cell-types very heavily, it’s true. But they still need to be targeting for delivery to cells-in-general.
To me the successful CureVac phase I trial for Rabies suggests that they do have a solution for the general targeting.
Given that Moderna is already doing their human trials this month and Biontic next month it seems they also have the problem of delievery to cells-in-general solved.