RT Journal
A1 Weinstock DM, Zuccotti G
T1 THe evolution of influenza resistance and treatment
JF JAMA
JO JAMA
YR 2009
FD March 11
VO 301
IS 10
SP 1066
OP 1069
DO 10.1001/jama.2009.324
UL http://dx.doi.org/10.1001/jama.2009.324
AB 
In February 2006, the US Centers for Disease Control and Prevention (CDC) reported that 92.3% of the circulating influenza A(H3N2) at that time was resistant to the adamantanes (amantadine and ramantidine), 1 of 2 pharmacological classes available for the treatment of influenza.1 The resistant viruses harbored an S31N amino acid substitution in the influenza M2 protein that confers resistance but does not affect virulence. Although resistance to adamantanes increased to 14.5% in the prior year,2 the dramatic increase in 2005-2006 came as a shock to both the medical and scientific communities and the public.3