merck says its clinical trial has shown that the drug cuts the risk of hospitalizations and deaths in half when given to high-risk people early in their infections. merck has stopped its trial and plans to seek emergency use authorization from the fda as soon as possible because they say of the positives outcomes they're seeing. it would be the first antiviral pill for covid. also big breaking news on vaccines. the cdc is now reporting that more than 77% of adults in the united states have gotten at least one covid shot. a lot of good news potentially here to discuss with cnn medical analyst, former baltimore health commissioner, could to see you dr. wen. i want your reaction to this news from merck. what could be the first antiviral pill for covid. why would this be important? >> so this is really big news, kate, and the reason is there is