I wonder if any stats or math go into this decision, and what the thresholds/limits of risk are? Or perhaps they're programmed into the criteria for what is ac

I wonder if any stats or math go into this decision, and what the thresholds/limits of risk are? Or perhaps they're programmed into the criteria for what is accepted as the eventual vaccine. Because this decision is most definitely making a call about the value of saved lives / avoided sickness, versus the likelihood of unintentionally caused sickness due to vaccine side effects. I wonder what the acceptable numbers / risk percentages are.