RT Journal
A1 Friedrich MJ
T1 FLu clues
JF JAMA
JO JAMA
YR 2010
FD May 5
VO 303
IS 17
SP 1686
OP 1686
DO 10.1001/jama.2010.525
UL http://dx.doi.org/10.1001/jama.2010.525
AB 
Experiments in mice revealed that the 1918 and 2009 pandemic flu viruses have certain similarities in a surface protein, hemagglutinin, which is instrumental in infecting cells. However, unlike seasonal viruses, which have sugar glycan molecules attached to hemagglutinin, they lack these sugar molecules. The glycans, which protect the virus from antibody detection, are a key feature adopted as a pandemic virus evolves into a seasonal strain.