New vaccine to protect against swine, human and bird flu; ward off annual shots

The vaccine strategy developed and tested by researchers at the University of Nebraska-Lincoln in the US can also eliminate the need for annual flu shots.

"This research sets the stage for developing universal influenza vaccines, so people won't have to go to the doctor and get a flu shot every year," said virologist Eric Weaver at the varsity.

"This vaccine will protect you against the different strains that are out there," Weaver said.

In the study, published in Nature Communications, swine vaccinated with the immunogens exhibited no signs of illness after being exposed to a commonly circulating flu strain. They also developed antibodies against a multitude of viruses from several decades and multiple species; and maintained their immune response throughout the six-month longitudinal study.

Post-experiment regression analysis indicated that the immunity would not dissipate for a decade, Weaver said.

The Epigraph vaccine, named after the computer software, used to design it, significantly outperformed a commercial vaccine used by the pork industry and a "wild type" vaccine based on naturally occurring strains with similar immunogens.

The study confirms previous research that demonstrated the vaccine design protected against the H3 influenza subtype.

The new results are particularly encouraging because H1 swine flu variants are detected twice as often as H3 variants -- and have nearly three times more genetic diversity, Weaver said.

"This H1 subtype is the largest and most genetically diverse subtype in pigs," Weaver said. "It's also among the viruses that jumped from swine to humans to cause the 2009 swine flu pandemic. It's a big target and one of the harder targets to hit."

The influenza A virus regularly infects as much as 15 per cent of the human population and causes thousands of deaths each year. Current vaccines often fail to provide long-lasting protection because of the genetic diversity and rapid mutation of proteins that help form the virus.

Another challenge in controlling influenza is that it infects multiple species: birds, swine, horses, and dogs, along with humans.

Swine often act as a mixing vessel because they are susceptible to human and bird flu variants, contributing to the evolution of novel forms of the disease that can be transmitted back to humans.

"If we can prevent influenza in swine, we can also prevent zoonotic jumps from avians to swine to humans, or from swine directly to humans. We could basically cut off this evolutionary arsenal or advantage that the virus has," Weaver explained. "The ultimate goal is to eliminate or eradicate influenza."