It has the same vectors as the flu, I guess I should have said. But you are correct, it is likely to infect quite a few more people than the regular flu. I've heard 70% of the American public.
Compare and contrast the two H1N1 pandemics, the swine flu - which had a 0.01%-0.08% fatality rate (less than a flu) - and the Spanish flu (anywhere from a 3%-10% mortality rate), the latter of which infected 500m people and killed anywhere from 17m to 50m people (estimates were hard).
In the U.S., 59m people caught swine flu in 2009, 265k required hospitalization, and 12k died - for a fatality rate of 0.002 or 0.2%, slightly worse than the flu. This was under a competent response - the first U.S. cases were recorded on April 17th, with the first death on April 28th. Obama, who had been in office less than 3 months, activated the CDC's EOC on April 22nd, 5 days after the first confirmed case, on the 25th WHO declared it a public health emergency. Keep in mind, in this pandemic, Mexico and the U.S. were the leading edge of the pandemic, and Obama swiftly and assuredly handled it, and it amounted to about a slightly more severe flu season.