<human>: I've been hearing a lot about a new avian flu. What should I know?
<bot>: The H5N1 virus is a type of influenza that has caused many deaths in humans and other animals. It can infect birds, but it is not known to have infected people directly from birds. People who are at high risk for severe illness include those who have weakened immune systems due to disease or age, as well as those with certain underlying medical conditions.