The two-dose vaccine uses the same messenger RNA (mRNA) technology used in the COVID-19 vaccines developed by Pfizer PFE.N with BioNTech 22UAy.DE and by Moderna MRNA.O. It delivers tiny lipid particles containing mRNA instructions to cells to make copies of so-called hemagglutinin proteins that appear on the surfaces of the flu virus. A universal vaccine wouldn’t mean the end of flu seasons, but it would replace the guesswork required to develop annual vaccines months before flu season each year. “The idea here is to have a vaccine that gives people a baseline level of immune memory to different strains of flu so that there will be far less illness and death when the next flu pandemic occurs,” study leader Scott Hensley of Perelman School. of Medicine at the University of Pennsylvania said in a statement. Unlike standard flu shots that provide one or two versions of hemagglutinin, the experimental vaccine includes 20 different types in hopes of getting the immune system to recognize any flu virus it might encounter in the future. In laboratory experiments, the immune system of vaccinated animals recognized the hemagglutinin proteins and defended against 18 different strains of influenza A and two strains of influenza B. Antibody levels induced by the vaccine remained unchanged for at least four months, according to a report published in the journal Science. The vaccine reduced signs of the disease and protected against death even when the ferrets were exposed to a different type of flu not included in the vaccine, the researchers said. Moderna and Pfizer both have mRNA flu vaccines in late-stage human trials, and GSK GSK.L and partner CureVac 5CV.DE are testing an mRNA flu vaccine in an early-stage human safety trial. These vaccines are designed to protect against only four strains of flu that are circulating recently, but could theoretically change each year. The universal flu vaccine, if successful in human trials, will not necessarily prevent infection. The goal is to provide lasting protection against serious illness and death, Hensley said. Questions remain about how to judge the efficacy and potential regulatory requirements for a vaccine against potential future viruses that are not currently on the market, Alyson Kelvin and Darryl Falzarano of the University of Saskatchewan, Canada, wrote in a commentary published with the study. While the promising results with the new vaccine “suggest a protective capacity against all subtypes of influenza viruses, we cannot be sure until clinical trials in volunteers are completed,” Adolfo García-Sastrem, director of the Institute for Global Health and Emerging Pathogens in Mount. Sinai Hospital in New York, it said in a statement. Report by Nancy Lapid. Edited by Christine Soares and Bill Berkrot
