The vaccine would be able to protect against all strains of the virus and could be a key weapon in avoiding a future flu pandemic, John Oxford said.
Dr Oxford, a virologist at Queen Mary University in London, said a new vaccine developed at the University of Pennsylvania represented a “huge breakthrough”.
The US team has created a vaccine based on the same mRNA technology used in the Covid-19 shots from Moderna and Pfizer.
Writing in the journal Science, they said their vaccine protected mice and ferrets against severe influenza, and the next stage will be clinical trials in humans.
Dr Oxford said the scientists in the US had mixed 20 strains of flu together and had a got a response to every strain. Current vaccines tend to protect against four strains of the virus.
“I cannot emphasise enough what a breakthrough this paper is,” Dr Oxford said. “The potential is huge, and I think sometimes we underestimate these big respiratory viruses.”
He said about 30 or 40 volunteers would be needed for the first clinical trial, with data possibly coming in within the next six months.
Researchers have been working on universal flu vaccines for many years, but the latest breakthrough is seen as a step towards protecting people in any future flu pandemic.
Dr Oxford said the shot, provoked high levels of antibodies, could save thousands of lives.
Andrew Freedman, a reader in infectious diseases at Cardiff University, said: “This vaccine has only been tested in animals to date and it will be important to investigate its safety and efficacy in humans.
“It does seem a very promising approach to the goal of producing a universal flu vaccine as well as vaccines that protect against multiple members of other viral families such as rhino and coronaviruses.”