I don't know if it's scientifically sound, but it appears reasonable. Supposedly backed by studies.
https://medium.com/@drhassaballa/new-research-on-masks-show-they-can-act-like-a-vaccine-5dbde9398dd4
https://medium.com/@drhassaballa/new-research-on-masks-show-they-can-act-like-a-vaccine-5dbde9398dd4