A team of researchers from Kansas State University recently developed vaccines for H5N1 and H5N9, two strains of avian influenza that are transferrable between birds and humans.
The two strains have been responsible for the recent need to cull millions of commercial turkeys and chickens. They also were the cause of death for hundreds of humans.
The researchers concentrated on developing vaccines for the avian influenza virus subtype H5N1, which is the newest and most active strain found in North African and Southeast Asian countries, including Egypt and Indonesia. H5N1 also has been reported in wild birds in the U.S.
The scientists combined two viruses (the Newcastle disease virus and the H5N1 virus) to create the H5N1 vaccine. They also combined the Newcastle disease virus and the H7N9 virus to create the H7N9 vaccine.
This new method of developing vaccines may help researchers create vaccines more quickly for new avian influenza strains.
"H5N1 is a zoonotic pathogen, which means that it is transmitted from chickens to humans," Jürgen Richt, Regents distinguished professor of veterinary medicine and director of the U.S. Department of Homeland Security's Center of Excellence for Emerging and Zoonotic Animal Diseases, said. "So far it has infected more than 700 people worldwide and has killed about 60 percent of them."
H5N1 has a particularly high mortality rate because it's hard to tell if poultry is infected with the virus.
"In Southeast Asia there are a lot of markets that sell live birds that people can buy and prepare at home," Richt said. "In contrast to the H5N1 virus that kills the majority of chickens in three to five days, chickens infected with the H7N9 virus do not show clinical signs of sickness. That means you could buy a bird that looks perfectly healthy but could be infected. If an infected bird is prepared for consumption, there is a high chance you could get sick, and about 1 in 3 infected people die."