New mRNA Flu Vaccine Could Reduce Hospitalizations and Deaths, Study Finds

A new mRNA flu vaccine awaiting FDA approval could reduce hospitalizations and deaths, according to a study published this week in Nature Immunology by researchers at WashU Medicine. If approved, the vaccine would be the first mRNA flu vaccine, and Moderna has completed clinical trials with the FDA potentially granting approval by early August.

Less than 50% of the population usually gets a flu shot. Because of the time it takes to manufacture the flu vaccine, companies have to predict which strain will be dominant and develop a shot for it. The problem is sometimes the virus changes very quickly, and then that vaccine doesn’t necessarily match the predominant strain that people might be getting sick with. The investigational mRNA vaccine, developed by Moderna, was found to be very good at stimulating the immune system and promoting different types of antibodies that could recognize different versions of the flu virus, researchers said.

The WashU study also found the new vaccine lasted longer than the 3-to-5 months of protection currently provided. In the study, researchers looked at immunity out to six months after people had received the vaccine, and saw that people who got the mRNA-based vaccine had higher antibody at six months after vaccination compared to the regular vaccine. Fewer sick people will mean fewer hospitalizations and deaths from the flu. Last year, 224 people died from complications from the flu in Missouri and 350 in Illinois.

The findings could have broader benefits to medicine. What has been learned about how the immune system responds to mRNA vaccines could potentially be applied to developing other vaccines to other viruses or bacteria that make people sick, and could help combat other diseases. Moderna has completed clinical trials, and the FDA could give approval by early August. Moderna plans to target the vaccine to the older adult population.