>>13538412This is unironically how shitty these studies are conducted:
1. Two groups (1 placebo, 1 vaccine)
2. Follow-up with them in a year
3. See which % test positive in that span of time
It's not controlled, and varies with each sampling event. It also is easy to eject participants that otherwise would bias the results. It's very pseudoscientific and not accurate. There is only way way of truly testing if a vaccine is effective and that is experimental design with lab introduced infections to both groups (suggested above).
