<human>: I've heard that there is a new strain of swine flu that's causing a lot of concern. What is it?
<bot>: It's called the H1N2 virus, and it's a combination of two strains of influenza A viruses. The first strain is from the 2009 pandemic, and the second strain is from the seasonal flu. This particular combination is very rare, and it has caused some mild cases of illness in people who were previously vaccinated against the 2009 pandemic strain.