August 6, 20262 min read Add Us On GoogleAdd SciAmIn a first, U.S. approves powerful new mRNA vaccine for fluThe shot, mFlusiva, was shown in a clinical trial to be up to 27 percent more effective than a standard flu jabBy Claire Cameron Adam Glanzman/Bloomberg via Getty ImagesJoin Our Community of Science Lovers!In a first, the U.S. has approved a flu vaccine that relies on mRNA technology—the same technology that underpinned the wildly successful Pfizer-BioNTech and Moderna COVID vaccines.The approval marks a sea change for the Trump administration. U.S. Health and Human Services (HHS) Secretary Robert F. Kennedy, Jr. is a vocal critic of mRNA vaccines, and his agency has canceled millions in funding for mRNA vaccine research. Indeed, the Food and Drug Administration initially declined to review Moderna's shot earlier this year, before reversing its decision just a week later.The vaccine is called mFlusiva and is also made by Moderna. The approval covers two of the most vulnerable populations to flu—adults aged 50 to 65, and adults aged 65 and up—on the condition that Moderna run a further clinical trial in the older group. Past trial data shows that Moderna's vaccine is around 27 percent more effective than a standard flu shot in protecting against the disease.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.For more than 70 years, flu vaccines in the U.S. have been manufactured using one of three techniques: egg-based vaccines (these are the most commonly available), cell-culture based vaccines and recombinant vaccines—these are vaccines that insert harmless genetic material from the virus into cells in order to trigger the immune system.Messenger RNA, or mRNA, vaccines work differently. Messenger RNA copies instructions from viral DNA and teaches the body's cells to build and recognize copies of viral proteins. The body can then create antibodies if it should ever encounter that protein again, enabling it to fight off infections.The other great advantage of an mRNA vaccine is that they can be rejiggered quickly to respond to emerging strains of a virus. Traditional flu vaccines are made to try and prevent infection from whatever three strains of the influenza virus scientists predict may circulate during the upcoming flu season. But they have to be made six months in advance of the actual flu season, which means these predictions can fall short of reality. Modern's new vaccine takes just two to three months to manufacture and roll out.The flu kills between 6,300 and 52,000 people each year, according to the Centers of Disease Control and Prevention (CDC). The public health agency recommends anyone over the age of six months who has no health reason preventing them to get the flu shot every year in order to protect against disease.It’s Time to Stand Up for ScienceIf you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.