No point: you will inhale after holding your breath, and the sigh will be deeper. It is better to avoid sick people, and not to work with such employees is the main thing. Patients are not recommended to go to work, and if they come, put on a mask, and let the others put on - there will be chances of not getting infected.
It doesn't make any sense, because you will still inhale. Microparticles are dispersed in the air, you will inhale them anyway.
It is optimal to simply close, turn away, and that's it. Or cover your mouth with your palm, and educated people, when they sneeze, cover themselves with a handkerchief.