Older people are more vulnerable to the influenza because over time their immune system starts to weaken and can’t fight diseases the same way it could while young and new. The effects of fighting the virus varies from different ages because although younger people have stronger immune systems, they all different, someone’s immune system can be strong enough to fight a simple virus while not so much a big virus like the influenza. However, another persons’ immune system could fight a virus like the influenza but not a small simple virus.