The U.S. winter virus season is in full force, and by one measure is the most intense in 15 years.

One indicator of flu activity is the percentage of doctor's office visits driven by flu-like symptoms. Last week, that number was clearly higher than the peak of any winter flu season since 2009-2010, according to data posted Friday by the CDC.

Of course, other viral infections can be mistaken for flu. But COVID-19 appears to be on the decline, according to hospital data and to CDC modeling projections. Available data also suggest respiratory syncytial virus (RSV) has been fading nationally. Head over to MedPage Today to read the full story.