The number of flu infections has surged across the country, with the highest numbers reported in New York, New Jersey, and Colorado. The CDC says 90% of these cases are linked to a new variant. Dr. Sarah Nosal, president of the American Academy of Family Physicians, explains how to stay healthy this flu season.  For more context and news coverage of the most important stories of our day, click here: nbcnews.com » Subscribe to NBC News: nbcnews.to/SubscribeToNBC » Subscribe to Here's the Scoop podcast: nbcnews.com/heres-the-scoop-daily-podcast Every day, NBC News helps people understand what’s happening and why it matters — through fact-based reporting, meaningful conversations, and powerful stories. From its leading news broadcasts — TODAY, NBC Nightly News, Meet the Press, and Dateline — to NBC News NOW, the 24/7 streaming news channel, plus chart-topping podcasts, the NBC News app, and NBCNews.com, NBC News keeps audiences informed and connected to t...