US - A Purdue University-led avian influenza vaccine project is aiming to develop new types of protection for birds after an award of $1.55 million from the National Institutes of Health.
The funding will allow the continuation of vaccine research led by Suresh Mittal, a professor of comparative pathobiology in Purdue's College of Veterinary Medicine, and includes collaborators at the Centers for Disease Control and Prevention.
Mr Mittal and CDC collaborators Suryaprakash Sambhara and Ian York created a vaccine in 2006 for the H5N1 bird flu virus. The team is now focusing on developing a broad spectrum vaccine capable of covering emerging influenza viruses that have the potential to cause the next influenza pandemic in humans, including H5N1 H7N3, H7N7, H7N9 and H9N2.
The new H7N9 influenza virus was found in China in 2013 and is responsible for 229 deaths and 665 cases as of May 2015, according to the World Health Organisation.
"These viruses begin in wild birds and as they evolve they expand to poultry and then to humans," Mr Mittal said.
"There is a very real risk that we will face an avian influenza pandemic at some point in the future and we need to be prepared. One important way to prepare is to develop and stockpile an effective vaccine.
"We can't predict what strain of the virus will be involved in a pandemic, so we need a vaccine that can offer protection across all of the strains."
Mr Mittal is working to create a vaccine that offers broad protection against multiple strains and mutations of the virus.
His method uses a harmless adenovirus as a vector to deliver avian influenza virus genes into the body where they produce influenza proteins that prime the immune system to fight an infection.
Genes conserved across all strains of avian influenza and those that are more difficult for the virus to change as it adapts are incorporated into the vector. The recipient's immune system is then primed to recognise and fight a wider variety of strains through a single vaccination, he said.
In addition, the mix of avian influenza virus genes included in the vaccine is strategically selected to expose the immune system to both the surface and internal components of the virus. This leads to a two-fold immune response of antibody and cell-based protection that offers a more robust immune defence, he said.
"Although this vaccine would offer variable levels of protection against all strains, it may not replace the need for a vaccine specific to the known strain," he said.
"What it will do is buy the time to create the strain-specific vaccine. Even if it can only offer partial protection, a broad spectrum vaccine will eliminate or lower the severity of symptoms, reduce transmission of the virus and save lives."
Mr Mittal's avian influenza vaccine work has been described in papers for The Lancet, Journal of Infectious Diseases, Clinical Pharmacology and Therapeutics, Molecular Therapy, PLOS ONE and Virus Research.ThePoultrySite News Desk