It is my opinion that mask use is a useful tool in mitigating the virus spread when you are exposed to the virus for a brief period of time, in a relatively well ventilated environment. In other words, if someone were to walk into my office and was several feet away it might prevent an illness if that exposure was brief and we both were masked. I believe it is counterintuitive to believe otherwise. I do not believe it would prevent an illness if the exposure was within a car for an extended period of time. Much of the time our interactions with other people follow the first scenario. None of your studies are useful in regards to that kind of exposure. The studies you mentioned in no way measure the overall benefits of wearing masks as it applies to Covid. The best evidence I can give you to the effectiveness of masks in the historically low incidence of influenza. You dismiss the studies that I posted because they are observational but they are at least measuring something that provides us with beneficial information. The CDC and medical journals think enough of them to publish them and you dismiss this as political. They may be observational but they are the best ones available at this point in time. It is not beneficial to know that a caregiver providing care to a sick individual needs more protection then a surgical mask. It is not beneficial to know that surgical masks do not protect family members in the household with a sick family member. We already know that. It is not beneficial to know that if you wear a mask out in public you get sick at roughly the same rate as those that do not wear masks. I object to the silly video which concludes at the end that masks are useless. I am not going to debate that the studies you posted are scientifically superior to the ones that I posted. I agree with you that they are but they are not measuring anything that I think applies to the wearing of masks according to todays CDC guidelines.No. Read my post. There were 2 RCT studies listed that tested source control (2010 & 2017). Source control is the wearer spreading the virus. And you don’t deal with the inability of cohort studies to demonstrate causation. Straw man arguments dont fool anyone.