surely made -- >> that's really interesting stuff. alexia, thank you for being here. covid-19 cases are dropping nationwide in some areas that have been hit the hardest. while there are some signs of hopes, the cold weather may create more problems. nbc's news correspondent, sam brock. >> reporter: for the first time in months, americans are feeling optimism. >> do you feel better hearing that? >> more relieved that covid cases are going down. >> hopefully by holidays, our numbers are lower. >> reporter: infection dropped around 40% since peaked level a month ago. dr. fauci predicting that could change. >> i strongly suspect that you are going to start seeing deaths