Last fall the CDC reported two cases of infection with this novel influenza strain in children in Indiana and Pennsylvania. By the end of 2011 that number had increased to 12, involving 5 states. So what's up with this?
What is it? It's a hybrid of a swine H3N2 known for several years, containing a genetic segment from the 2009 novel H1N1 strain.
Human to human transmission capability? If so it appears to be inefficient according to the CDC. The possibility exists, because while some of the cases were attributable to direct animal contact some others were not.
Severity of the illness? In the very limited experience so far it seems to be no worse than ordinary seasonal flu.
Is this year's vaccine effective? Probably not.
Will Tamiflu and Relenza work? Probably according to the CDC.
Above and beyond the ordinary flu swab which patients should have PCR testing specifically for A(H3N2)v? For now, according to CDC: 1) those who've been near pigs and 2) young children with acute respiratory illness in states where it has been reported.
That's the status today. It will change.