A leading scientist has said that a universal influenza vaccine that protects against all strains of the virus may be available in the next two years.
An experimental vaccine based on the same mRNA technology used in the highly successful Covid strike has been found to protect mice and rodents from severe influenza, paving the way for human clinical trials.
A vaccine developed at the University of Pennsylvania may be ready for use the following winter, said Professor John Oxford, a neurologist at Queen Mary University of London who was not involved in the work.
“I can’t stress enough what a breakthrough this paper is,” Oxford told BBC Radio 4 Today. “The potential is huge, and I think sometimes we underestimate these great respiratory viruses.”
Researchers have been working on universal flu vaccines for more than a decade, but the latest breakthrough, published in the journal Science, is seen as a major step toward a jab that could help protect humans from 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 for the flu viruses in circulation. The new vaccine is designed to prime the immune system against all 20 influenza subtypes A and B, potentially arming the body against any influenza virus that emerges.
The world last experienced an influenza pandemic in 2009 when a virus that jumped from pigs to humans spread across the globe. While this outbreak was far less deadly than health officials had feared, the 1918 flu pandemic demonstrated just how dangerous new strains could be, which could kill tens of millions of people.
Giving people a “basic” level of immunity against a full range of influenza strains could lead to much less illness and death when the next flu pandemic hits, said Dr. Scott Hensley, a researcher on the team at Penn State. Experiments in mice and rodents found that the mRNA flu vaccine elicited high levels of antibodies that were stable for several months and protective against the virus.
While results from animal tests 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 a shot that could protect against viruses that could cause a pandemic should be approved, but it has not yet been shown.
“This vaccine has only been tested in animals so far and it will be important to validate its safety and efficacy in people,” said Dr Andrew Friedman, Reader in Infectious Diseases at Cardiff University. “It appears to be a very promising approach to achieving the goal of producing a universal influenza vaccine in addition to vaccines that protect against many members of other viral families such as rhinoviruses and coronaviruses.”
Current flu vaccines do not protect against influenza viruses with pandemic potential, said Adolfo García-Sastre, director of the Institute for Global Health and Emerging Pathogens at Mount Sinai Hospital in New York. “This vaccine, if it works well in people, will make that happen.”
He added, “Preclinical studies, in experimental models.” “It’s very promising, and although it indicates a protective ability against all subtypes of influenza viruses, we can’t be sure until clinical trials are done in volunteers.”