New results from Richard Webby, PhD, at St. Jude Children’s Research Hospital and colleagues published in the international open-access medical journal PLoS Medicine suggest that the answer might be yes.

The H5N1 avian flu virus is quite different from the seasonal H1N1 and H3N2 flu viruses most humans have been exposed to, which is why many scientists believe that H5N1 could start a new pandemic.

Webby and colleagues wondered whether immunity to the human type 1 neuraminidase (huN1) in H1N1 influenza virus strains (and vaccines made to protect against them) could provide protection against avian H5N1 influenza virus, which contains the closely related avian type 1 neuraminidase (avN1). In the new study, they investigated this possibility in mice and in a small group of humans.

The results indicate that a vaccine containing huN1 makes mice produce antibodies that partly protect them against avian H5N1 infection. In addition, the human data suggest that a proportion of people have low titer antibodies against H5N1 influenza because of prior exposure to H1N1 viruses or routine influenza vaccination.