The H1N1 “swine flu” outbreak early in 2009 had two side effects: news accounts fueled widespread fear of an epidemic and they made repeated claims that this virus was still “evolving.”
The World Health Organization eventually classified this flu outbreak as a “pandemic,” the first time a virus has reached this status in 41 years. But the term refers to how quickly and widely the virus can spread, not its deadliness.
Furthermore, the virus is an example of mutation, not evolution in the usual sense of the word. The mutations did not add any new genetic information to the virus. They merely altered existing information, allowing the swine virus to become contagious, and sometimes deadly, among humans.