A universal flu vaccine that protects against all strains of the virus could be available within the next two years, according to a leading scientist.
An experimental vaccine based on the same mRNA technology used in highly successful Covid bites has been shown to protect mice and ferrets against severe flu, paving the way for clinical trials in humans.
Professor John Oxford, a neurologist at Queen Mary University of London, who was not involved in the work, said the vaccine developed at the University of Pennsylvania could be ready for use the following winter.
“I cannot stress enough how breakthrough this article is,” Oxford told the BBC’s Radio 4 Today programme. “The potential is huge, and I think sometimes we underestimate these big respiratory viruses.”
Researchers have been working on universal flu vaccines for more than a decade, but the latest breakthrough, published in Science, is seen as a major step towards a vaccine that could help protect humans against a potentially devastating flu pandemic.
Seasonal flu vaccines, which protect against up to four strains of the virus, are updated each year to ensure they are a good match with circulating flu viruses. The new vaccine is designed to prime the immune system against all 20 influenza A and B subtypes, potentially arming the body to fight any flu virus that arises.
The world last experienced a flu pandemic in 2009 when a virus that jumped from pigs to humans spread around the world. Although this epidemic was far less deadly than health officials feared, the 1918 flu pandemic demonstrated how dangerous new strains could kill tens of millions of people.
Giving people a ‘baseline’ level of immunity to the full range of flu strains could lead to far less illness and fewer deaths in the next flu pandemic, team researcher Dr Scott Hensley said. in Pennsylvania. Experiments in mice and ferrets showed that the mRNA flu vaccine elicited high levels of antibodies that were stable for several months and protective against the virus.
Although animal test results are promising, clinical trials are needed to see if the vaccine protects humans in the same way without causing problematic side effects. The vaccine raises questions for regulators about whether to approve a vaccine that could protect against viruses with pandemic potential, but which have yet to emerge.
“This vaccine has only been tested in animals to date and it will be important to study its safety and effectiveness in humans,” said Dr Andrew Freedman, Reader in Infectious Diseases at Cardiff University. . “This seems a very promising approach to the goal of producing a universal influenza vaccine as well as vaccines that protect against several members of other viral families such as rhinoviruses and corona-viruses.”
Adolfo García-Sastre, director of the Institute for Global Health and Emerging Pathogens at Mount Sinai Hospital in New York, said current flu vaccines do not protect against influenza viruses with pandemic potential. “This vaccine, if it works well in humans, would achieve that goal.”
“The studies are preclinical, in experimental models,” he added. “They show great promise and, although they suggest protective capacity against all influenza virus subtypes, we cannot be sure until clinical trials in volunteers are completed.”