According to WHO, currently licensed pandemic vaccines closely match circulating viruses and are expected to provide good protection.
The agency says vigilance for changes in the H1N1 virus includes monitoring to detect possible influenza infections in susceptible animals, both mammals and birds, as well as humans.
It says that while most influenza A viruses circulating in mammals preferentially infect a single species, cross-species transmission is known to occur.
WHO notes that concern has traditionally focused on pigs, which are susceptible to infections from human and avian influenza viruses, as well as swine influenza viruses.
WHO says that pandemic H1N1 infections have been reported in turkeys in Chile and Canada and in a few pet animals in the United States but these were isolated events and pose no special risk to human health.
Gail Walker, United Nations Radio.
duration: 1'11"