Through the use of some powerful bioinformatics techniques, a team of European researchers has designed two new universal flu vaccines based on an array of epitopes from the influenza virus. The investigators predict that their vaccine design could provide protection for up to 88% of known flu strains worldwide in a single shot—potentially ending the winter flu season.
“Every year we have a round of flu vaccination, where we choose a recent strain of flu as the vaccine, hoping that it will protect against next year's strains,” explained co-author Derek Gatherer, Ph.D., lecturer of biomedical and life sciences at Lancaster University, U.K. “We know this method is safe, and that it works reasonably well most of the time. However, sometimes it doesn't work—as in the H3N2 vaccine failure in winter 2014–2015—and even when it does it is immensely expensive and labor intensive. Also, these yearly vaccines give us no protection at all against potential future pandemic flu.”
The researchers have devised two universal vaccines: a USA-specific vaccine with coverage of 95% of known U.S. influenza strains and a universal vaccine with coverage of 88% of known flu strains globally. The USA-specific vaccine was generated because the bioinformatic tools that the researchers used (EPISOPT) are able to make predictions for the five main ethnic groups in the U.S. (Black, Caucasian, Hispanic, Asian, and native North American), allowing for diverse genetic background of coverage.
“We designed two epitope ensemble vaccines comprising highly conserved and experimentally verified immunogenic influenza A epitopes as putative non-seasonal influenza vaccines; one specifically targets the US population and the other is a universal vaccine,” the authors wrote. “The USA-specific vaccine comprised 6 CD8+ T cell epitopes…and 3 CD4+epitopes…. The universal vaccine comprised 8 CD8+ epitopes…and the same 3 CD4+epitopes.”
The findings from this study were published recently in Bioinformatics in an article entitled “Towards the Knowledge-Based Design of Universal Influenza Epitope Ensemble Vaccines.”
Universal flu vaccine work is immensely important as global pandemics are always looming on the horizon. Previous pandemics include the “Spanish flu” of 1918 and the two subsequent pandemics of 1957 and 1968, which led to tens of millions of deaths. Even today, the World Health Organization says that annual flu epidemics are estimated to cause up to half a million deaths globally.
“It doesn't have to be this way,” Dr. Gatherer proclaimed. “Based on our knowledge of the flu virus and the human immune system, we can use computers to design the components of a vaccine that gives much broader and longer-lasting protection.”
“A universal flu vaccine is potentially within reach,” added co-author Pedro Reche, Ph.D., associate professor of Immunology at Complutense University, Madrid. “The components of this vaccine would be short flu virus fragments—called epitopes—that are already known to be recognized by the immune system. Our collaboration has found a way to select epitopes reaching full population coverage.”
The research team is now actively seeking partners in the pharmaceutical industry to synthesize their vaccine and begin the necessary preclinical trial experimentation for proof-of-principle.
“Epitope-based vaccines aren't new, but most reports have no experimental validation,” concluded senior study investigator Darren Flower, Ph.D., a reader in pharmacy at Aston University. “We have turned the problem on its head and only use previously-tested epitopes. This allows us to get the best of both worlds, designing a vaccine with a very high likelihood of success.”