mRNA Technology Successfully Tested for Universal Flue Vaccine

mRNA Technology Successfully Tested for Universal Flue Vaccine researchers may be one step closer to creating the long-desired universal flu vaccine as a result of mRNA technologies. 

In a study published online in Science on November 24, researchers from the University of Pennsylvania’s Perelman School of Medicine stated that they had created an mRNA-based vaccine that is effective against all 20 known variations of the A and B flu viruses.

For the production of a successful seasonal flu vaccine, some foresight is required. There are numerous influenza viruses, but each vaccine can only target up to four of them. If scientists fail to correctly make predictions about different strains each season, that typically leads to a waste of a lot of time and money. Moreover, it puts the public at risk, as they stay unprotected from the flu. This is why the mRNA technologies at work here are in such high demand.

Each year, experts forecast which four influenza viruses will cause the most damage during the coming season. On the basis of those strains, they create a “split virion protein vaccine,” which involves growing the viruses in chicken eggs before cutting them up to render them inactive. These inactive fragments are then injected into the body, prompting the immune system to generate antibodies against the four different strains.

The issue with this method is that it necessitates the development of new vaccines every year, some of which may prove inadequate against the season’s main flu strains if initial predictions are inaccurate. The split virion protein vaccine can’t protect against a wide range of strains because it can only handle up to four of them. Hence, scientists have tried developing universal vaccines targeting common parts of the flu virus, albeit without much success.

In the Penn study, mRNA was used to generate an antibody response to Hemaglutinin (HA) proteins that protrude from the surface of the virus and enable it to infect host cells. The 20 subtypes of A and B influenza viruses that infect humans have their own unique HA proteins.

Scientists tested the vaccine’s efficacy by administering it to mice and ferrets and then exposing them to flu viruses representing 20 different lineages 28 days later. They discovered that while not all of the animals were completely immune to infection, they were protected from death or serious illness. Four months after receiving the vaccine, their antibody levels were still quite high. 

Additionally, the vaccine was effective in rodents that had already contracted the flu prior to vaccination. The vaccinated rodents developed antibodies against all 20 lineages, protecting them from lethal doses of influenza A, B, and C viruses.

Scott Hensley, Ph.D., and senior author said in a press release, “The idea here is to have a vaccine that will give people a baseline of immune memory to diverse flu strains so that there will be far less disease and death when the next flu pandemic occurs.”

The researchers are currently planning clinical trials in humans. They also want to include young children in the trials because they think the vaccine has the potential to create a long-lasting immune memory against all 20 flu variations.