We have had a great filter for 300,000 years. It's called a nose. Mouth breathers have been brainwashed and have no idea how to use the nose because the Illuminati Central Planners have taught the medical doctors and nurses that we visit to teach us to take deep breaths through our mouths.
Praniyama which is the breath exercises of Hatha yoga and kriya yoga teach you to use your nose as a filter. This is why you get colds but don't die. Virus and bacterial infections are introduced here along with healthy organisms that promote metabolic health. When your nose produces mucus and you swallow it, it makes you sick but it also via your stomach introduces microorganisms to your immune system. Here natural immunity begins its manufacturing process. Also the nasal cavity absorbs energy ( prana) which is in oxygen, nitrogen and is a basic building block for life itself.
So we don't need witch doctors and paid statist shills to tell us what we need to live. Why?
Because we've been living for 300,000 years in our current human form and we've made it this far without central planning devils. In fact we've made it this far in spite of the central planning devils who strive to cull humanity at every chance they get.
Not Today Satan!