|Health Policy Outlook logo 130| No. 4, May 2009 As the H1N1
swine flu continues to spread, the focus has turned to the
prospects for quickly developing a vaccine that can protect
Americans. So far, most infections in the United States have
been mild, but even if this flu strain turns out to be no more
potent than the seasonal flu, there is reason to believe that
more people will be stricken--and with more serious illnesses.
This summer--not the season in which flu traditionally spreads--
may provide a backstop that limits the spread of the virus. But
even under optimal circumstances, we could still see slow but
continued transmission of H1N1 through the spring and summer,
followed by a spike in cases this fall, when flu season returns.
Regular flu is associated with 250,000-500,000 deaths worldwide
every year, including those of 30,000-50,000 Americans. So far,
swine flu appears relatively mild outside of Mexico. For reasons
we cannot yet explain, the virus is infecting more young people
than elderly and more