This new solution has just completed the first stage of human clinical trials, designed to evaluate its safety. It passed with flying colors, and though the sample size was small – just 65 people – it's a promising start to what will hopefully be a long-term life saver.
"An influenza virus vaccine that results in broad immunity would likely protect against any emerging influenza virus subtype or strain and would significantly enhance our pandemic preparedness, avoiding future problems with influenza pandemics as we see them now with COVID-19," says microbiologist Florian Krammer.
"Our chimeric hemagglutinin vaccine is a major advance over conventional vaccines which are often mismatched to the circulating strains of virus, impacting their effectiveness. In addition, revaccinating individuals annually is a huge and expensive undertaking."
The vaccine is so named because it targets the hemagglutinin protein that binds the influenza virus to host cell receptors in the body. Influenza vaccines usually encourage the body to produce antibodies that target the globular head domain, or tip, of the protein. In this case, though, researchers took aim at the stalk domain further down, closer to the virus's shell.
While the flu virus is typically able to use a process called antigenic drift to counter neutralization by mutating the head of the hemagglutinin protein, that escape route isn't available through the stalk part. It's a fixed target rather than a changing one.
"The beauty of this vaccine is that it's not only broad, but multifunctional with stalk-specific antibodies that can neutralize many kinds of influenza viruses," says microbiologist Adolfo García-Sastre." ScienceAlert
