Patients are now enrolling in an early-stage clinical trial to test a universal flu vaccine based on messenger RNA technology, the National Institutes of Health announced Monday.

Scientists hope the vaccine will protect against a wide variety of flu strains and provide long-term immunity so people don’t have to get a shot every year.

Messenger RNA, or mRNA, is the technology behind modern‘sand PfizerThe widely used Covid vaccines. NIH played a crucial role in the development of the mRNA platform used by Moderna.

“A universal flu vaccine could serve as an important line of defense against the spread of a future flu pandemic,” Dr. Hugh Auchincloss, acting director of the National Institute of Allergy and Infectious Diseases, said in a statement Monday.

The universal flu vaccine trial will enroll up to 50 healthy people ages 18 to 49 to test whether the experimental shot is safe and produces an immune response, according to the NIH.

The study will also include participants receiving a quadrivalent flu vaccine, which protects against four strains of the virus, to compare the experimental universal shot with those currently on the market.

The universal shot was developed by researchers at the National Institute of Allergy and Infectious Diseases. The clinical trial is recruiting volunteers at Duke University in Durham, North Carolina.

The current generation of flu shots They provide important protection against hospitalization, but the effectiveness of injections can vary greatly from year to year.

Right now, scientists have to predict months in advance which flu strains will dominate so vaccine makers have time to produce the shots before respiratory virus season.

The dominant flu strains can change between the time experts select strains and manufacturers release injections. In some seasons, the shots do not adapt well to the circulating strains and are less effective as a consequence.

Flu vaccines reduce the risk of disease by 40-60% when combined well with circulating strains, according to the Centers for Disease Control and Prevention. But in some years, the effectiveness of vaccines has been as low as 19% because the injection was not properly adjusted.

According to the CDC, the flu killed between 12,000 and 52,000 people annually in the US between 2010 and 2020, depending on circulating strains and vaccine coincidence.