(from Newswise )
The flu is nothing to sneeze at. Two Texas Tech Researchers Working Toward Universal Flu Vaccine with a five-year grant from the National Institute of Allergy and Infectious Diseases, Harvinder Gill and Steve Presley are targeting the most unchanging parts of the flu virus.
The Spanish flu pandemic of 1918 killed an estimated 50 million people worldwide; by comparison, about 16 million people died in World War I. And flu pandemics aren’t just a thing of the past. Despite advances in both technology and vaccines, the 2009 swine flu pandemic caught the world unprepared and an estimated 150,000 to 500,000 people died.
The Centers for Disease Control and Prevention (CDC) estimate that, each year since 2010, between 9.3 million and 49 million people have become ill from flu infections, 140,000 to 960,000 people have been hospitalized, and 12,000 to 79,000 have died. The flu’s economic impact is an estimated $10 billion per year, with a loss in earnings of about $16 billion per year.
With flu vaccines widely available, why does this keep happening? One obvious reason is that many people don’t get vaccinated each year. A larger problem, however, is that current vaccines cover only the three or four strains of the flu that the World Health Organization expects to be the most prevalent each year: trivalent vaccines contain two influenza A strains and one influenza B strain, while quadrivalent vaccines contain two influenza A and two influenza B strains. That means all the other strains that exist are able to infect people, unchecked.
Thanks to a five-year, $3.46 million grant from the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, two Texas Tech University researchers already widely known for their work in immunotherapy and infectious diseases are trying to solve this. Harvinder Gill, the Whitacre Endowed Chair in Science and Engineering and an associate professor in the Department of Chemical Engineering within the Edward E. Whitacre Jr. College of Engineering, and Steve Presley, a professor and chairman of the Department of Environmental Toxicology within the College of Arts & Sciences, have teamed up to develop a universal flu vaccine.
“The concept behind a universal flu vaccine is to create a vaccine that shows enhanced breadth of protection and ideally protects against strains that are significantly different from each other,” Gill said. “Such a vaccine is expected to offer many advantages, including not having to change the formulations every year and providing greater and consistent vaccine efficacy year after year. Naturally, the universal vaccine also will be capable of preventing flu pandemics.”
To develop an effective universal flu vaccine, Gill and Presley are targeting parts of the flu virus that don’t change significantly from strain to strain. Although much of the flu virus has a high propensity to change, some of its protein segments remain highly consistent. By directing the vaccine-induced immune response toward these segments, the pair are confident they can create a single vaccine that will protect against many strains.
“We are exploiting two of these protein segments to make a universal vaccine,” Gill said. “These two segments lie on proteins found on the surface of a flu virus: one is an ion channel called M2 and the other is called neuraminidase (NA). The M2 segment is highly conserved in influenza A strains, but the NA segment is conserved in both influenza A and B strains. Thus, we are hopeful of making a universal flu vaccine against both type A and type B flu viruses.”
A major benefit of the vaccine Gill and Presley have been developing is that, unlike current vaccines, it does not require refrigeration so it can have a longer shelf life and be more readily transported to places where refrigeration is not feasible.
“We have seen that our vaccine formulation can be dried into a solid powder, which even after storage at 50 degrees Celsius for two weeks can be re-suspended in water and maintains efficacy in protecting vaccinated mice against lethal flu infection,” Gill said.
The vaccine ultimately will be tested against a broad range of type A and type B flu strains, but it is already showing promise.
“Until now, we have tested the vaccine with just the M2 protein segment and it was able to protect vaccinated mice against four different strains, including the 2009 pandemic strain and the highly pathogenic H5N1 bird-flu strain,” Gill said. “It is difficult to predict success; however, with the addition of yet another conserved protein segment – the NA segment – we expect the vaccine to be even more effective.”