coronavirus April 15, 2021 5:18 pm 3rd Vaccine Shot May Be Needed: Pfizer CEO The CEO of Pfizer says people might need to get a third COVID-19 vaccine shot. Janelle Wang reports. US & World Videos 2:19 San Francisco barbershop struggles to stay open after pandemic 0:51 Alameda County using dogs to detect COVID 3:57 Interview: Doctor's perspective on COVID 4 years after shutdown started 2:27 Marking 4 years since COVID-19 shut down the Bay Area 2:09 CDC updates COVID isolation guidelines