>>14419274Yep. Many of the positive effects from asking are in a combined strategy environment where n95 is used in accordance with strict protocols often with multifaceted plan of attack - masks, sterilization, and quarantine. Sterilization being no small part where hospitals are running medical grade ventilation and alcohol. The next factor in many of these studies have the disease is question is often focused to a narrow window of comparison. The study group apparent protection is only over a certain time frame. If a third of the protected doctors get sick compared to the control group over a six week window, then the study group will still have similar infection rate on a yearly time scale, assuming no reinfection, aka sterilizing immunity, natural immunity, or plain immunity. This makes protections exceptional in preventing localized outbreaks, but practically worthless for any sort of sustained viral threat. This doesn't seem obvious, but if you consider the whole population is under threat for an initial infection over the year than it is clearly true. Mitigation effects must be extremely effective to be useful over longterm exposure.
There is also no telling how much risk is presented in the uncontrolled environment. These type of protective approaches may be much stronger than a study shows, but there is no way to tell if a person gets infected on the job or through some other external coinciding event. An arbitrary level of protection can be achieved very realistically over short intervals and small areas/regions. The costs grow exponentially depending on certainty levels, but not all costs are recoupable or justified. A decon checkpoint may be certainly justifiable if some nerve agent is deployed in a region and you want to make sure none of it comes back on the soldier. Using shit masks on children indefinitely because the boogeyman might accidentally use them to infect their teacher is not.
