See my prior posts. I acknowledged this. The technology may have been around for decades, but there's no safety data on long term risk in hundreds of millions of people. While I'm not overly concerned with prime/boost regimen, with annual booster, if it is deemed the vaccine has <12 month protective immunity, then they need to understand why, not just keep jabbing people. As a scientist I am sure they are already looking into this should immunity be somewhat short lived.