>> reporter: and if you tested positive after exposure, how long do you need to isolate? those rules are changing. just last week, the cdc issued new guidance lowering recommended isolation time from ten days to five days for asymptomatic people. critics worry that new guidance may allow infectious people to return to work. >> our guidance was conservative before. >> reporter: and what about those soaring hospitalizations? if omicron is supposed to be milder than delta, in most cases, then why are more than 100,000 people hospitalized with covid-19 for the first time in nearly four months? the u.s. department of health and human services, also, says about three-quarters of hospital beds across the country are full. and one in seven are for covid patients. >> when you have so many, many cases, there is still the danger that you are going to have a surging of hospitalizations that might stress the healthcare system. so it is kind of like a very interesting, somewhat complicated issue. >> reporter: complicated, for