CBRN PAPR suits are extremely expensive and in far too short supply to be used by first responders generally. It is also not widely understood that masks aren't very protective against virii. Doctors and medical personnel wear them during surgeries so that the droplets they breathe out don't infect their patients, not to keep themselves uninfected. Wearing a mask in public is a courtesy to protect the public, not yourself. You need a lot more than a paper mask to protect yourself, as the suits worn by the military personnel on the plane show.

Thanks!