you for having me on. you know, one of the reasons we're discovering these in the uk is because they're doing really extensive testing of their viruses in a way that we are not. so, we don't know if it's in the u.s. or not. it is concerning that we have now several variants that seem to be spreading more easily. but we do need to start looking for it more aggressively here in the united states. >> and are children more susceptible to infection from these mutations that we're seeing? >> there's a lot we're still learning about this. it does appear from preliminary data that kids may be more susceptible to being infected. doesn't necessarily mean they're going to get any sicker. one of the highlights of this disease has been that kids don't usually get very sick. i think that will be true for this variant, as well. >> okay, dr. jha, thank you so much, as always. next tonight, we're on the front lines with paramedics at the epicenter of this pandemic right now, in orange county, california. six potential covid cases in just 30 minutes, risking their own lives to answer each and every call. abc's kaylee hartung is there. >> reporter: tonight, this is