Whats different about the H1N1 virus that sets it apart from the usual seasonal flu?
SS: In some cases, infection with H1N1 appears to generate more severe symptoms with a slightly longer duration then in past years, and with higher rates of mortality, especially in individuals with other risk factors (e.g., respiratory problems). The main difference is in the genetic make-up of the virus, which acquired whole new stretches of DNA that differ from last year’s predominant strain. This differs from the small DNA changes that are typical from year to year for influenza virus. Therefore, our immune systems are unlikely to have previously encountered a strain of influenza that looks much like this one. This leaves most of us more vulnerable to infection. Q: Is it more contagious than other viruses? SS: The H1N1 does not seem to be significantly more contagious, or infectious, than a typical influenza virus. However, as a population we are more vulnerable to infection because we have little if any immunologic memory of a virus that looks like this, and this one looks very di
