is covid. 2021 began with a vaccine rollout, still has ended as the deadliest year of the pandemic and misinformation has proven dangerous to people's health. we have been talking to dr. fauci across the pandemic learning about his guidance and what to do if the facts change and new variants emerge. >> the best way you can prevent the virus from evolving and mutating is to prevent it from replicating because it is an interesting tenet of virology. the only way a virus can mutate is if you allow it to replicate. so when you have a lot of infection in your country, when you're getting 3 to 400,000 new infections a day, the virus has an open playing field to replicate so much that it starts to mutate. that's when you get the dangerous mutations. so one of the best ways to prevent that from happening in