the vast majority are benign but every now and then, dumb luck on the part of virus, it will figure out a configuration to really set us back. that appears to be what it's done now. and it is because of the number of new cases around the world. we've not successfully vaccinated the number of people we need to in the united states and certainly not around the world, and that gives the virus myriad chances to have new viruses and each one is opportunity for mutation. >> 25% of the eligible u.s. population still hasn't been vaccinated according to the cdc. doctor, more than 30 countries including the u.s. have identified omicron cases. do you think stricter testing for people flying to the u.s. will slow a potential spread? >> by a little bit, maybe by a week or two. the case reported in minnesota was someone who went to new york, didn't travel abroad. it's already here. as we test more, we'll find more cases here. i understand the restrictions,