positive, doctors say a number are getting serious cases of covid. >> covid in a short period of time has been a leading cause of death in this country. i think it's time we stop downplaying the significance of covid for children. >> reporter: the omicron variant is impacting the unborn. holy cross hospital is temporarily shutting down its maternity ward because of a surge in cases among the hospital staff. in the texas pediatric hospital, there were seven cases when the year began. today it's 70. >> the numbers passed our recent peak at the delta surge. >> reporter: doctors say low vaccination rates for young children are the cause. >> we're beginning to vaccine 5 to 11-year-olds but when you look at who's been in the hospital, it's the 5-year-olds to 11-year-olds who have not yet seen the vaccine. >> reporter: as the omicron variant surged in recent weeks,