Scientists discovered the genetic flaw that explains the reason why flu makes some people seriously ill. They in fact found a human gene called IFTIM3 that influences how people respond to flu infections. It explains why some people experience mild flu symptoms while others are hospitalised.
People who carried a particular variant of IFTIM3 and in large quantities had resisted the viruses in lungs while the others whose IFITM3 levels were lower, the flu virus could replicate and spread more easily, causing more severe symptoms.
This discovery could explain that why the vast majority of people infected with swine flu (H1N1) during the 2009-2010 had only mild symptoms like coughs and sneezes while others got seriously ill and died. The discovery could also help develop new medicines and vaccines against bird flu.