Grounding of 9/11 flights delayed flu season: study

Here's something positive that came out of 9/11 flight grounding. It gave scientists data to show that flight travel increases the spread of flu, by the fact that flu season peaked 13 days later than normal in 2001/2 flu season, due to the grounding of flights. In France where they didn;t ground flights flu season peaked at it's normal time.
CBC News: Grounding of 9/11 flights delayed flu season: study