Flu viruses may trigger deadly immune system response

Researchers studying the 1918 influenza pandemic believe overactive human immune response, rather than the virus itself, was responsible for the massive world wide death toll. Immune overreactions may also have caused most of the deaths in the 2009 swine flu outbreak, which killed 18,000 people world wide. A Washington Post story by David Schultz quotes Trish Perl, senior epidemiologist at Johns Hopkins Hospital, who explains many severe infections cause the immune system to go into overdrive. She says that may explain why the 2009 swine flu killed more young than elderly victims: the stronger immune systems of young people may also be more prone to overreaction. A VaccineNewsDaily.com story reports the research could lead to new drugs against flu viruses and new ways to treat infections.