If it can be given prophylactically, can they develop a vaccine that would get the body to produce the same antibody?
/Spoken like the true science novice that I am
Why can't they make vaccines that also do that?
Yes, that's also the goal. I don't know how they would do it, and haven't researched this part, but here's a guess, totally out of the air, like I said, this is much further from the areas that I've said before are not my field...
The spike protein (like all proteins) is made up of a chain of amino acids. The mRNA is also a chain, made up of nucleotides, which provides the instructions for the cell to make the spike protein. Three nucleotides say put this amino acid here, the next three nucleotides say put that amino acid next to it, etc. So the sequence of nucleotides in this particular mRNA (in the vaccine) are the instructions for creating the sequence of amino acids in the spike protein.
Once the immune cells see the newly manufactured spike protein, they start to make antibodies against it. The antibodies are also proteins, but they're much smaller than the spike protein, so they can create antibodies that attack different parts of spike. One antibody might bind only to the bottom of spikes, another only to the tip. In this picture, the long spike protein is shown as a red and blue strand, folded up into the spike shape. The blue part is the part that will bind to the ACE2 receptor. The antibodies are smaller, with a light blue Y-shaped antibody able to bind the RBD, and a pink antibody able to bind to the red part of the spike.
from a video by Tyler Starr, the first author of the article
&t=186s
This novel antibody, which they found in one person, binds to a sequence of the amino acids which are hidden inside the spike RBD, and are "visible" to the cell only when the spike is about to bind the ACE2 receptor and the spike RBD opens up to expose that amino acid sequence.
So perhaps if there were a slight change in the amino acid sequence, the spike RBD could be locked in that open position, and thereby the hidden region would always be exposed. They could then create the appropriate mRNA sequence that would be used to make the appropriate modified spike that always displays that previously hidden region. Then, when the immune cells see that particular spike, they'll make the antibodies to the previously hidden region.
Or perhaps they can learn what signal normally causes the spike to open up when it approaches the ACE2 receptor. Perhaps it's some chemical, and then the vaccine we have today, with mRNA for a normal spike, might also include a chemical signal that would cause the spike to open and expose that region to the immune cells.
I'm totally making this up, don't have time now to research it.
But one other thing I found last night is that this general approach, looking for antibodies that bind to a broad range of viruses, is being studied by other scientists. Here's one published a couple weeks ago, Ultrapotent antibodies against diverse and highly transmissible SARS-CoV-2 variants. The 5th author is a frum guy, clearly not on DDF or he'd be answering these questions. Maybe
@Dan can invite him for an AMA?
https://science.sciencemag.org/content/373/6556/eabh1766