The flu, like a cold, is a respiratory infection but is caused by an entirely different group of viruses - namely the influenza A, B and C viruses. Perhaps the best way to prevent the flu is to get an annual flu shot before the flu season hits.
I called Lufthansa, and they told me that there are Economy Plus seating sections on the Bangalore to Frankfurt and Frankfurt to Chicago legs. But, since I bought tickets through United, they told me I can't get any seat assignments until check-in in Bangalore unless I work with United.
Delta is in the process of adding Economy Comfort seating, which features up to an additional four inches of legroom and increased recline, on many of its long haul flights. On Delta's Airbus A330-300s that have been reconfigured, rows 10-14 are the Economy Comfort rows.