A jab that protects against every form of flu could be available within five years, scientists have said, after a “promising” trial in animals.
The influenza virus constantly evolves, requiring new vaccines each year. However, researchers in the US have developed an “innovative” approach targeting a part of the virus that does not mutate.
An early trial in monkeys showed that the vaccine, designed based on a 100-year-old virus, generated “a robust immune response” against a modern variant.
“Even after almost 100 years of evolution, the virus can’t change those critically important parts of itself,” said Prof Jonah Sacha of Oregon Health & Science University. This raises hope for a “one and done” vaccine that could provide lifelong immunity against an evolving virus.
“This could actually become a vaccine in five years or less,” said Prof Sacha.
Current flu vaccines target spike proteins on the virus’s surface, which can evolve to elude antibodies. The new vaccine technology, initially developed to fight HIV, uses a harmless herpes virus, cytomegalovirus (CMV), to deliver a piece of genetic code from the flu virus to the body’s cells, mimicking an infection.
The vaccine targets the virus’s core, which does not mutate over time. The team tested the jab on 11 monkeys infected with H5N1, a bird flu virus with potential pandemic capability. Six monkeys inoculated against the 1918 Spanish flu survived exposure to contemporary H5N1, while unvaccinated monkeys succumbed to the disease.
The researchers’ approach focuses on effector memory T cells in the lungs, which recognize proteins in the virus core that do not evolve.
Prof Sacha said, “It worked because the interior protein of the virus was so well preserved.” This study also opens potential for developing a vaccine against H5N1 in humans.
Douglas Reed, associate professor of immunology at the University of Pittsburgh’s Centre for Vaccine Research, emphasized the need for rapid validation and deployment of a new vaccine if H5N1 were to cause a pandemic.
The vaccine technology, licensed by Vir Biotechnology, could also work on other viruses, such as Sars-CoV-2, providing long-lasting immunity. Prof Sacha stated, “It’s a massive sea change within our lifetimes.”
The research, supported by the Bill & Melinda Gates Foundation and the National Institutes of Health in the US, signifies a major advancement in how we address infectious diseases.
