US : Why H1N1 could be fatal to young adults

Via UPI :

" NASHVILLE, Dec. 6 : U.S. and Argentine researchers suggest some young people died during the 2009 pandemic flu from an immune system response.

However, they say, the H1N1 vaccine offers protection and those patients who died were overwhelmingly unvaccinated. Many fell ill before a vaccine was available.

Researchers, led by Dr. Fernando Polack of Vanderbilt University Medical Center in Nashville, have identified a biomarker -- C4d -- a protein molecule that signals the body has responded with a massive immune response that can inflict -- potentially fatal -- damage to the lungs."