Influenza viruses can evade human immune system

London: Influenza commonly known as "flu” can hide itself undetected in an individual's body by the person's immune system, reveals a study. The influenza virus that affects mainly the nose, throat, bronchi and occasionally lungs contains a protein that helps in outsmarting the immune system -- which can track viruses and alert the body of the entry of foreign virus into the human cells to multiply.

"The virus contains a protein that masks the virus entering the cell. In this way, the influenza virus can spread more easily before the immune system recognises that it is a virus and attempts to fight it," said Christian Holm, associate professor at Aarhus University in Denmark.