The first approval in the U.S. for a messenger RNA-based flu vaccine was signed off on by the U.S. Food and Drug Administration on Wednesday. The new vaccine, mFlusiva, will be available for adults aged 50 and older. Dr. Isaac Bogoch, a Canadian-based infectious disease specialist, said it’s great news in the health-care community. “In people over the age of 50, it was, relative to the standard flu vaccine, about 27 per cent more effective,” Bogoch told CTV Your Morning on Friday. He said he wouldn’t be surprised if Canada rolled out the new shot for the upcoming flu season. “At face value, that’s fantastic, we should be extremely happy that we have a more effective flu vaccine,” he added. The mFlusiva, developed by Moderna, is designed to prompt the body to produce cells to fight influenza and trigger an immune response, which could allow faster updates to treat different flu strains. More than 40,000 people took part in a study for the new vaccine, and Moderna has said it will expand trials for seniors. Standard flu vaccines are egg-based and rely on viral proteins to inoculate the immune systems. Because there are so many different influenza strains and limited resources to produce and distribute vaccines, scientists make educated estimates on which strain poses the largest risk. However, the flu can be unpredictable, leading to a given year’s vaccines being less effective if scientists don’t target the right strain. “The traditional flu vaccines take about six months, from the time they decide what the strain is that they’re going to create the vaccine against, to the time it’s mass produced and ready for the general public,” Bogoch explained. He warned against two risks: the strain changing in the field while the shot is being developed, or the vaccine strain being slightly altered during the manufacturing process in the incubation eggs. “That’s why traditional flu vaccines are anywhere from 30 to 50 per cent effective. They tend to have a range of as low as 10 per cent to 60 per cent in your reduction of risk of flu,” Bogoch said. He added that “all of that is negated with mRNA technology,” which because of its shorter turnaround time — about three months — is much more reliable. ‘Have honest conversations’ Although the mRNA technology is generally more effective and timelier, it has more severe side effects, which could turn people off from taking it. “The side effects were significantly worse than the standard flu vaccine,” Bogoch said. He highlighted that about 66 per cent of patients reported pain at the injection site, while only 30 per cent complained about pain from the standard vaccine. Similar ratios were found for headaches, fatigue and general muscle aches and pains. “On the one hand, great, it looks like it’s a more effective vaccine, and on the other hand, there’s more side effects,” he said. “We have to ask ourselves: how good is a vaccine if people are choosing not to take it because of the side effects?” Bogoch said that the study behind the shot was good, a phase-three clinical trial. He added that more data would be needed, but for now, the study was enough to work off. There will be follow up research on the vaccine after it was distributed, Bogoch said. “I think we just have to have honest conversations with the general public about what the benefits are, what the potential downsides are and what the alternatives are.”
