The scientists identified a protein that inactivates the flu virus before it can mutate.

VOA: special.2009.03.04

The standard flu vaccine causes the body to produces antibodies, which target parts of the virus that frequently mutate.

VOA: standard.2010.07.21

"They don't mutate,and the reason they don't mutate is that if they try to, the virus can't survive if you have mutations in these sites."

VOA: standard.2010.07.21

The virus did not mutate to a more virulent form.

VOA: standard.2010.01.18