This isn't true. No RCTs have ever been performed on the original vaccines and the subsequent variants. And to the extent that other kinds of experiments (retro

This isn't true. No RCTs have ever been performed on the original vaccines and the subsequent variants. And to the extent that other kinds of experiments (retrospective cohort studies, etc.) have been done, they've almost universally found diminished effectiveness against mild illness. Effectiveness of the original vaccines against Omicron infection, in particular, is essentially zero after a few months: https://www.medrxiv.org/content/10.1101/2021.12.20.21267966v2 https://www.medrxiv.org/content/10.1101/2021.12.20.21267966v... It should be noted that the vaccines appear to remain highly effective against severe illness, even without boosting. The mRNA vaccines, in particular, seem to raise a robust, long-lasting cellular immune response, even though antibody levels rapidly fall. One of the downsides of the unusually rapid approval process for the Covid vaccine was that it was impossible to see this pattern in a randomized trial that lasted only a few months. This led "experts" -- people who really should have known better -- to oversell the shots as a form of sterilizing immunity. They are not. There are good reasons vaccines take a long time to develop.