Pfizer says Covid-19 vaccine is 95 percent effective, FAA clears Boeing 737 Max to fly again after two fatal crashes, and new fallout after Trump fires top cybersecurity official.Watch NBC Nightly News With Lester Holt at 6:30 p.m. ET 5:30 p.m. CT (or check your local listings).00:00 Intro02:05 U.S Tops 250,000 Coronavirus Deaths04:03 Pfizer: Coronavirus Vaccine 95 Percent Effective05:39 FDA Approves First At-Home Covid Test06:01 States Seeking To Reassure Vaccine Will Be Safe06:35 Inside The Red Zone Where Spread Is Exponential'08:04 How To Curb The Spread Of Coronavirus09:03 NYC Shuts Down School As Positivity Rises10:31 Boeing 737 Max Cleared To Fly After Deadly Crashes12:39 New Fallout After Trump Fires Election Security Chief13:37 Trump Pursuing Election In Key States14:27 Biden: Transition Delay Threatens Vaccine Rollout15:09 Americans Rush To Get Tested Before Thanksgiving16:40 Foods To Boost Your Immune System18:01 Owl Rescued From Rockefeller Center Christmas Tree