H5N1 avian influenza virus is causing sporadic cases in humans
Luca Bruno/Associated Press/Alamy
If the H5N1 avian influenza virus causes a pandemic, older people may have better immunity than younger people because they have been exposed to closely related viruses in the past.
In previous outbreaks of H5N1 infection, older people less likely to get infected with a virus Scientists therefore hypothesized that the former group may have stronger immunity to the virus than younger people. This may be due to older adults being exposed to influenza strains closely related to H5N1, called H1N1 and H2N2.
Source: www.newscientist.com
