Wellness

What is Swine Flu, or H1N1?

ByGreg Poland, M.D., Professor of Medicine, Director, Mayo Vaccine Research Group, Mayo Clinic

September 25, 2008, 1:56 PM

May 27, 2009 -- Question: What is swine flu, or H1N1?

Answer: In some respects it's just like any other influenza virus. It's a virus that causes a predominantly respiratory illness. What's unique about this swine flu is that it is a mutated type of virus so that nobody in the U.S. or probably world wide has any immunity to it. Hence it's ability to cause widespread infections.

Up Next in Wellness—

Twin sisters conjoined at the head underwent successful separation surgery: Hospital

September 16, 2026

Flu season is coming: What to know about new vaccine, when to get your shot and more

September 15, 2026

Celine Dion returns to the stage amid stiff-person syndrome battle

September 14, 2026

Lindsay Clancy trial shines spotlight on maternal mental health

September 3, 2026

Shop GMA Favorites

ABC will receive a commission for purchases made through these links.