How scientists battle to stay ahead of flu
4 January 2013 Last updated at 16:03 GMT
As flu brings its usual misery to thousands over the winter, our minds turn to avoiding it or getting back on our feet after a bout of it.
Experts at the Medical Research Council (MRC) have spent much of the past 100 years studying the virus and, in fact, researchers there were the first in the world to identify influenza.
BBC London's Matthew Morris talks to Dr John McCauley and Dr Rod Daniels of the MRC National Institute for Medical Research about their work to keep one step ahead of the virus.
Footage courtesy of British Pathe.