coronavirus September 17, 2020 9:23 pm How Herd Immunity Works With COVID-19 News4’s Doreen Gentlzer explains what herd immunity is and what it means for the coronavirus. Local 2:14 Opioid crisis: National drug take back day on Saturday 2:55 Concussion treatment: Returning to school and limiting screen time may help, study finds 2:39 What to know about ADHD medication and pregnancy 2:08 How to pick the best running shoes for outdoor exercise 3:41 Nail biting: A psychiatrist shares tips