by Laurie Fickman, University of Houston Credit: Unsplash/CC0 Public Domain Breathe in, breathe out. That’s how easy it is for SARS-CoV-2, the virus that causes COVID-19, to enter your nose. And though remarkable progress has been made in developing intramuscular vaccines against SARS-CoV- 2, such as the readily available Pfizer, Moderna, and Johnson & Johnson vaccines,...