in the cold, especially the elderly. >> reporter: and the fda now says early data suggest rapid antigen tests still work to detect omicron, but they may have reduced sensitivity. >> we still are encouraging their use. they may not work as well as they had for the delta variant. >> reporter: and tonight, children's hospitals are sounding the alarm about the accelerating covid impact, with pediatric hospitalizations doubling in the last month. >> our most precious commodity in this united states of america is our children. and right now, we're on fire. >> concerns for so many parents. trevor ault joining us now. i want to go back to the cdc director pointing to practical reasons behind those new recommendations on isolation and quarantine, saying many people just don't follow the guidance to begin with. >> reporter: yeah, that's right, whit. the cdc director says they've seen some stud dies show that wn people are asked to isolate, only a third of them do it. she says they wanted to give