vaccination of adults. that's the best way to protect children and infants, jonathan. >> and dr. propst, as i mentioned before, you're coming to us from houston, texas. and i would love to know from you what does a pediatric patient with covid go through? we know what it means for adults, the problems breathing. but for a child, an infant what is that experience like for them? >> it is so variable. the youngest child i have treated with covid-19 in recent weeks was a 5-week-old. i have had, of course, teenagers. so really there's a huge range both in age and in presentation. worst-case scenario, of course, children can face respiratory failure and require intubation and intensive care.