Vaccine developed in Nebraska could signal end to annual flu shot
A new vaccine strategy developed and tested by a team from the University of Nebraska-Lincoln could signal an end to the annual flu shot routine.
The possible breakthrough is laid out in newly published research in Nature Communications. The study, “Epitope-Optimized Vaccine Elicits Cross-Species Immunity Against Influenza A Virus,” describes a vaccine that protects against H1N1 swine flu and can also protect against influenza in birds and humans.
Lab work is conducted at the University of Nebraska-Lincoln. (Courtesy of UNL)
“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 Eric Weaver, director of the Nebraska Center for Virology who led the Nebraska research team. “This vaccine will protect you against the different strains that are out there.”
Named after computer software
According to a UNL news release, swine vaccinated with immunogens designed in Weaver’s lab showed no signs of illness after being exposed to a commonly circulating flu strain. They developed antibodies against multiple viruses from several decades and several species and maintained their immune response throughout the six-month study.
Based on the study results, Weaver said that immunity in pigs could last at least a decade. “We hope that would translate into humans,” he said.
Called the Epigraph vaccine, after computer software used to design it, the vaccine significantly outperformed a commercial vaccine used by the pork industry and a “wild type” vaccine based on naturally occurring strains with similar immunogens.
Both the National Institutes of Health and the U.S. Department of Agriculture’s National Institute of Food and Agriculture supported the study.
The newly published findings confirm previous research that showed the vaccine design protected against the H3 influenza subtype. Weaver said 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.
“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 UNL team noted that influenza A infects as much as 15% of the human population and causes thousands of deaths annually. Today’s vaccines often lack long-lasting protection because of the genetic diversity and rapid mutation of proteins that help form the virus.
Another challenge in controlling influenza, according to UNL, is that it infects multiple species, including 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,” the statement said.
UNL offered as an example the 2009 swine flu pandemic, transmitted from hogs to humans. About 25% of the human population was infected with the new variant, and more than a half million people died from it in the first year, according to some estimates.
“If we can prevent influenza in swine, we can also prevent zoonotic jumps from avians through swine to humans, or from swine directly to humans,” Weaver said. “We could basically cut off this evolutionary arsenal or advantage that the virus has.”
A goal, he said, is to produce a pediatric vaccine that will protect people throughout most of their life — and, ultimately, eradicate influenza.
Flu strains back to 1930
Weaver’s vaccine strategy, which has been patented, used the Epigraph software to study genetic codes of more than 6,000 strains of influenza virus from 1930 to 2021 and create a vaccine that represents their most common epitopes.
Epitopes were described as regions on a virus that trigger the immune system to produce antibodies to neutralize the virus and to send T-cells to destroy infected cells. Also according to the news release, some epitopes disappear as the virus evolves. The computer-derived Epigraph strategy increases the likelihood that the vaccine contains the epitopes needed to trigger an immune response and prevent illness.
“Our ability to understand how viruses evolve has increased exponentially in the past 20 years,” Weaver said. “What I see on the horizon is a third wave, where we go from good vaccines to universal, lifelong vaccines.”
The UNL team now plans to test a vaccine to protect against both H1 and H3 strains of influenza.
Weaver said that he doesn’t have a projection yet for when a longer-lasting flu vaccine for people might be available, but said his team is in discussions with a biotechnology company to pursue the human vaccine.
