[QUOTE=ectoBgone;1646318053]This actually jogged my memory on something I wanted to ask you. I feel lazy for not researching it much myself, but isn't the booster simply a re-spin of the vaccine encoded for the antigen associated with delta? Is it a "booster" because the dosing is smaller or does something make it fundamentally different than the original vaccine? Aside from the sunk cost of the existing vaccine already manufactured, why not just reset the current vaccines administered to encode the most recent variant? I thought that was part of the benefit of mRNA technology. It should allow for quick pivots for variants. Thanks for your time.[/QUOTE]
I'm told some trials have started with updated spike proteins, but I haven't searched clinical trials .gov to know if they are enrolling or in startup. Those should go fairly quickly, and it seems to me that a third shot with an updated antigen would be more useful than another shot of the wild type vaccine. That said, I don't know if a 3rd shot of a new strain would properly be called a booster shot.
The current booster shots are the same vaccine as we've been receiving already. No change in antigen or dose. Useful for people who don't have a normal immune system response, and they may temporarily increase cross strain resistance since you'll have more antibodies and Tk/Th cells for a while, but I don't think there's enough data to say how much benefit each cohort or population of people will get.
The CDC was recommending people get a third shot of the same vaccine. I don't know if they still are, but I told my parents that it makes more sense to me to get a shot of Moderna. They've had Pfizer's vaccine, so I figure they might as well modernize it. Without real data, it's purely speculation that you may get slightly broader protection if you mix brands.