What is Swine Flu, or H1N1?

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.