Dedomenocracy: govern by placebo
The vaccine as a population placebo has to have a similar reaction on a population. The population-placebo vaccine has to have adverse effects normally associated with vaccines. There needs to be people who will suffer from reactions, and even some some people die from the vaccine. This would prove to the public that this is real, and if it is real, it might be effective. The placebo effect is on the entire population in order calm it back to something closer to normal.