Are a bit encouraging regarding the severity. >> so with us for more tonight, thank goodness, dr. nahid bhadelia, an infectious disease physician, founding director of boston university's emerging diseases policy, and research. i'm guessing you want to be encouraged by those words. i also know the business you're in is one where you are constantly cautioning us against jumping to conclusions. >> that's right. and brian, i think the inherent virulence of a pathogen, right, what part of severity of disease is actually caused by a variant is really hard to tease apart because it's also a function...