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.
In some general admission events, a ticket may still assign the holder a specific section of the venue (e.g., balcony or floor), with the choice of seat within that section. General admission can also refer to a scheme in which seating is available; however, it is not pre-assigned. Typically in this scheme, seat selection is on a first-come, first-served basis. A common example of this scheme is most movie theaters in the United States.