Global circulation patterns of seasonal influenza viruses vary with antigenic drift
The analysis of more than 9, 000 haemagglutinin sequences of human seasonal influenza viruses over a 12-year time period shows that the global circulation patterns of A/H1N1 and B viruses are different from those of the well characterised A/H3N2 viruses; in particular the A/H1N1 and B viruses are shown to persist locally across several seasons and do not display the same degree of global movement as the H3N2 viruses.
