Research biologists may have found a protein on the highly pathogenic H5N1 avian flu virus that chickens’ immune systems can be better trained to attack.
University of Guelph pathobiology professor Shayan Sharif, whose team recently published a paper on its findings in the peer-reviewed online journal PLoS One, said the team’s work may not only protect chickens but control H5N1’s transmission from birds to humans.
Vaccines are available to protect domestic poultry from H5N1 virus, but “very little” is known about chickens’ immune response to the H5 flu.
To that end, “we have found one of the molecular determinants of the H5N1 avian influenza virus that can induce immune responses in chickens,” Sharif said in a release Tuesday.
Sharif’s research team has identified a small peptide in the hemagglutinin (HA) antigen, a protein found on the surface of the H5 virus.
The team’s work shows that the peptide is recognized by the chicken’s T-cells, which attack the virus directly and also trigger production of antibodies against the infection.
The Guelph team’s discovery marks the first time scientists have identified a T-cell epitope — a protein on a virus particle recognized by the immune system — on a flu virus found in chickens.
“This is an important step toward developing more efficacious vaccines against H5 avian influenza in chickens,” said Sharif. “We may be able to use this epitope in future vaccines to not only protect domestic flocks but also to prevent or control the spread of the virus from birds to humans.
“However, this still needs to be confirmed experimentally and that will be the focus of our future research.”
The deadly “high-path” strain of H5N1, which has been circulating in Europe and Asia for over a decade, has crossed over with fatal results in 262 people worldwide, out of 442 confirmed human infections since 2003. Its human victims have generally caught it from direct contact with infected birds.
While it doesn’t transmit readily between people like its headline-grabbing cousin H1N1, it’s long been feared the more lethal H5N1 could mutate into a form more easily transmissible between birds and people, or even between people.
H5 avian flu is commonly found in wild birds such as migratory waterfowl that are usually unaffected, but those birds are known to transmit it to domestic birds including chickens, in which it can cause illnesses ranging from no symptoms at all to a severe epidemic that kills all infected birds.