What meaning does the auther refer the word "universal" to here?

I think the definition about the word "universal" in the headline listed in my dictionaries does not fully convey what the author intends to deliver.

What does it exactly mean here?

Context:


Universal Flu Vaccine Moving Closer


ScienceDaily (July 18, 2010) — A universal influenza vaccine -- so-called because it could potentially provide protection from all flu strains for decades -- may become a reality because of research led by scientists from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

http://www.sciencedaily.com/releases/2010/07/100716125837.htm