Avian, or bird, flu, has devastated commercial chicken and turkey operations in the Midwest, resulting in the culling of millions of birds. But beyond its economic impact there are serious health concerns.
In Asia strains of the avian flu have passed from bird to humans, with health officials estimating 1 in 3 humans who contract the illness die.
Now, researchers in the U.S. have developed a vaccine for two new strains of bird flu. While providing some protection it is also expected to help researchers make additional vaccines for new strains of avian influenza more quickly.
As a result, the number and intensity of large-scale outbreaks at poultry farms could diminish and transmission to humans become less of a threat. Jürgen Richt, Regents director of the U.S. Department of Homeland Security's Center of Excellence for Emerging and Zoonotic Animal Diseases says it could also lead to flu vaccines for pigs and other livestock.
H5N1
Richt and his colleagues at Kansas State Univesity focused on H5N1, a new strain seen mostly in Indonesia, Egypt and other Southeast Asian and North African countries. H5N1 also has been found in wild birds in the U.S. but is not believed to be widespread.
"H5N1 is a zoonotic pathogen, which means that it is transmitted from chickens to humans," Richt said. "So far it has infected more than 700 people worldwide and has killed about 60% of them. Unfortunately, it has a pretty high mortality rate."
The new vaccine for H5N1 came about when scientists put 2 viruses together. Tests show that the combined virus was an effective vaccine for chickens against both Newcastle disease virus and H5N1.
H7N9
Next the scientists focused their efforts on the bird flu subtype H7N9, which has been infecting birds in China since at least 2013. Since then there have been about 650 cases of H7N9 in humans and some 230 people have died. There are aspects of the new virus that make it more dangerous than previous strains.
"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."
Again, tests showed that chickens vaccinated with the new Newcastle virus-based vaccine were protected against H7N9.
Welcome news
A vaccine that could stop bird flu from spreading would be welcome news to the poultry and egg industries. Nearly 40 million U.S. chickens have died or been exterminated as poultry producers try to stop the spread of the disease. That’s more than double the number lost in the last outbreak back in the 1980's.
All of this is having an impact at the supermarket. Some turkey producers have warned of possible shortages of the Thanksgiving Day staple and egg prices are skyrocketing.
The Wall Street Journal has reported wholesale prices for the eggs sold at supermarkets are up about 85% at $2.20 a dozen in parts of the country. Restaurants specializing in breakfast are also feeling the pinch and will likely pass along the higher costs to consumers.
A vaccine that could limit the carnage would likely alleviate much of this economic fallout, though it isn’t known how quickly that could happen.