Thanks for the resource! I'm making the transition between KN95 masks and N95 respirators at present. My only reservation about the article is that people will see his summary of the numbers on how effective current intramuscular mRNA vaccines are against *Omicron* specifically and oversimplify it down to "vaccines are useless!" But then again, most of the people likely to do that probably aren't reading the Substack of a cardiologist-turned-researcher. I don't know. Fingers crossed about the nasal vaccines, though.