SYDNEY, Feb. 19 (Xinhua) -- Australian researchers have paved the way for a universal flu vaccine by identifying immune cells, called killer T cells, which can fight all variants of the influenza virus.

The Peter Doherty Institute for Infection and Immunity and Monash University revealed the joint effort on Tuesday, calling it a "paradigm -shifting discovery, which could lead to an influenza vaccine that does not need to be updated annually."

Past research had shown these killer T cells being present in an immune response to some, but not all of the A, B and C influenza viruses.

"Influenza viruses continuously mutate to evade recognition by our immune system, and they are vastly diverse, making it nearly impossible to predict and vaccinate against the strain that will cause the next influenza pandemic," lead researcher and PhD student Marios Koutsakos said.

"We have identified the parts of the virus that are shared across all flu strains, and sub-strains capable of infecting humans, and then investigated if we could find robust responses to those viral parts in healthy humans, and influenza-infected adults and children."

The discovery was a key breakthrough for the team who will now focus on creating a universal influenza vaccine to reduce the impact of pandemic events and seasonal influenza around the globe.