happens early in the course of the illness, a day or two prior to symptoms and two to three days after. the number of children admitted to hospitals with covid is up 35% in just the past week. new york city has seen a five-fold increase this month. meanwhile, sickouts from covid have forced airlines to cancel or delay thousands of flights worldwide. the infectious disease expert in the u.s., says the administration is working hard to increase access to testing across the country. >> it's a combination of people concerns appropriately about omicron, which is spreading so rapidly, as well as the fact that we're in the holiday season and people want to get tested before they start mingling with their family and their friends and traveling. so, it really has made a major upsurge in demand for the tests, when we are already in a situation where, quite frankly, we don't have enough tests at this particular point in time.