The flu causes three million to five million cases of severe illness every year and up to 650,000 deaths, despite the fact that we have had vaccines to fight it for eight decades.
“The bottom line is that the flu vaccines we have aren’t good enough,” said Nicholas Heaton, a virologist at Duke University School of Medicine.
For about three decades, researchers have been working on flu vaccines based on mRNA, which powers the Moderna and Pfizer coronavirus vaccines. They are made quickly from scratch instead of being grown for months in chicken eggs, which could make them better matched to each season’s flu strains. They may also provoke a stronger immune response.
When Moderna formed in 2010, influenza was one of its first targets. It ran an encouraging clinical trial of an mRNA flu vaccine in 2016, and in early 2020 it was preparing for a new trial — when Covid emerged.
Moderna had to shelve the trial, but it and other companies are still working on the technology. Approval could be a few years off, and efficacy may not be as high against the shape-shifting flu as it has been for the coronavirus, but researchers are hopeful it will improve on “not good enough.”