New York, Nov 26: An mRNA-based vaccine that protects against all 20 known subtypes of the influenza virus has been created by scientists and early tests showed that it offered significant protection against otherwise deadly flu viruses.
Researchers from the Perelman School of Medicine at the University of Pennsylvania in the US believe that this might be used as a broad preventative measure against upcoming flu pandemics.
The “multivalent” vaccine is made with the same messenger ribonucleic acid (mRNA) technology as the SARS-CoV-2 vaccines made by Pfizer and Moderna. Penn was the originator of the mRNA technology that made it possible for the Covid-19 vaccines.
Even when the animals were exposed to flu strains distinct from those employed in the vaccine’s development, tests on animal models revealed that the vaccine significantly decreased symptoms and protected against death.
“The idea here is to have a vaccine that will give people a baseline level of immune memory to diverse flu strains, so that there will be far less disease and death when the next flu pandemic occurs,” said study senior author Scott Hensley, a professor of Microbiology at in the Perelman School of Medicine.
Periodically, influenza viruses generate pandemics with high mortality rates. The most well-known of them was the “Spanish flu” pandemic of 1918–19, which claimed the lives of at least tens of millions of people around the world.
Pandemics can begin when one of these strains of flu virus leaps to people and picks up modifications that make it better suited for spreading among humans. Flu viruses can circulate in birds, pigs, and other animals.
According to researchers, current flu vaccines only provide “seasonal” protection against recently circulating viruses and cannot be expected to provide protection against novel, pandemic strains.
“It would be comparable to first-generation SARS-CoV-2 mRNA vaccines, which were targeted to the original Wuhan strain of the coronavirus,” Hensley said.
“Against later variants such as Omicron, these original vaccines did not fully block viral infections, but they continue to provide durable protection against severe disease and death,” he added.
When the experimental vaccine is administered and absorbed by the recipients’ cells, copies of a crucial flu virus protein for each of the 20 influenza subtypes begin to be produced.
“For a conventional vaccine, immunising against all these subtypes would be a major challenge, but with mRNA technology it’s relatively easy,” Hensley said, who is currently designing human clinical trials with his colleagues.