Why does H1N1 seem to attack healthy young adults more than sick and elderly people, who are most affected by the ordinary seasonal flu?
Young adults have a healthy immune system that launches a massive counterattack of antibodies against the flu virus. Unfortunately, the counterattack can cause an overwhelming inflammation that damages other organs, such as the lungs. Elderly people with weaker immune systems are less likely to suffer from such harmful inflammation. Older people who were exposed to earlier flu epidemics might also have some residual immunity in their systems.
