Onelove the remarkable success of mRNA vaccine In protecting people against COVID-19, scientists are turning their attention to another annual respiratory illness: the flu. Both Moderna and Pfizer — the maker of the first U.S. Food and Drug Administration (FDA)-approved vaccine using mRNA technology — are studying whether the introduction of influenza virus genetic material on that platform will have the same effect or not.
On September 14, Pfizer announced that the first volunteers received its flu mRNA shot; The Phase 3 study will involve more than 25,000 U.S. adults 18 years of age and older who will be randomly assigned to receive an experimental vaccine or a placebo. In June, Moderna announced Late-stage testing of an mRNA-based flu vaccine targeting the same strains of flu is expected to circulate this fall and winter. Moderna’s study will involve 6,000 adults in the United States and other countries in the Southern Hemisphere, countries that experienced flu season a few months before the United States. Both trials are currently at a similar stage; Neither company has provided a timeline for when they can expect results and, if those results are positive, when they can submit a request to the FDA for approval.
However, public health experts hope it won’t be for long. The advantage of the mRNA platform is that it is flexible and generalizable. In theory, scientists only need to transfer genetic material, or mRNA sequences, from one virus to another. The point is to figure out which specific genes trigger the immune system best — and that’s where researchers have decades of flu experience that they don’t get with SARS-CoV-2.
Both companies target four strains of influenza that the World Health Organization (WHO) has identified in february because it is more likely to circulate during the 2022-2023 flu season in the Northern Hemisphere. Preliminary studies by both Pfizer and Moderna show that the influenza mRNA vaccine is safe, leading to ongoing late-stage studies that will focus more specifically on demonstrating whether the shots are effective in protect people from the flu or not. Current vaccines, using decades of technology that involve growing influenza viruses in chicken eggs, have traditionally been moderately effective. When WHO experts accurately predict and match vaccine strains with the last flu strains circulating, the shots protect people from serious illness. 40% -60% of the time. In the years the match was not tight, the effectiveness of the shot dropped to about 20%-30%.
mRNA vaccines should eliminate this mismatch. Because the technology is more flexible, manufacturers can create images with new gene sequences in about three months or so. That means that if a bad mismatch occurs during a flu season, scientists have the ability to produce a new batch of flu mRNA vaccines that target the matched genetic sequences in the same season.. That could therefore reduce flu hospitalizations and deaths, which are still relatively high. The virus causes up to 700,000 hospitalizations and 52,000 deaths in the US each year.
While influenza mRNA vaccination would be a huge step forward in vaccine technology, there may be other ways to protect people from respiratory illness with the combined shots. In a separate trial, Moderna is also working on combination vaccines that could immunize people against both SARS-CoV-2 and influenza in a single shot.
Other must-read stories from TIME