Originally Posted by
Mesabah
The vaccines produce the antibody CR3022; That lasts about 9 months, I would expect the same, or slightly longer for the vaccines.
Technically, you can avoid the vaccine, and get the direct infusion if you have the cash.
Your immune system will retain T-cells (aka memory cells) which will quickly mobilize your system to make the right antibodies on-demand. So efficacy duration is a combination of factors, including t-cell memory and response time, in addition to lingering antibodies. So the only way to know for sure is to wait and see, although the mfgs probably have a rough idea by now based on the blood-chemistry of the early-stage trial volunteers. But even that's not even the entire story, they really will need to collect real-world clinical data, as opposed to making the call based on lab chemistry.
It's possible they might do a just-in-case booster before they know for certain, rather than risk lost efficacy in 100's of millions (billions?) of people.