Suggest if there is so much doubt about the mRNA vaccine, stick to the traditional weakened/attenuated type of vaccine. Edward Jenner used it and the technology is still being used.
I love his analogy about playing in dirt when he was young - perhaps these guys should go work at the morgue or ICU without PPE and "roll around" in the dirt. They sure could need some helping hands.
Speak to your colleagues, some have caught COVID-19 - the ones who've had more than mild symptoms. Ask them how it was. There are more out there these days.