Background The high mutation rate of influenza A virus hemagglutinin
segment brings great challenges to its long-term effective testing and
subtyping. Method We analyzed the conserved sequences of hemagglutinin
subtype H1-H9 by breadth first, and designed primers for HA subtyping
based on conserved sequences. Results Our conserved sequence searching
method get high specificity conserved sequences on H1-H9 subtypes
respectively. And PCR experiments show that primers based on conserved
sequences can be used in influenza A virus HA subtyping. Conclusions
Conserved sequences based primers are expected to be the long-term
effective influenza A virus HA subtyping tools.