Flu Fighters Get a Lift From the Battle Against Covid

The billions of dollars plowed into Covid-19 vaccines have yielded promising results in tests by Pfizer, BioNTech, and Moderna—welcome news in the battle against the global outbreak. But for scientists studying another respiratory ailment known to trigger pandemics—influenza—the news is equally important, because it augurs an acceleration of their research. “What you are seeing are several technologies that will be tested all at once,” says Gregory Glenn, research chief for Novavax Inc., which is working on Covid and flu vaccines. “It’s kind of the world’s greatest technology bake-off: You’re going to see how the vaccines perform.”

The influenza viruses that infect people change constantly, so twice a year—around the peak of the flu seasons in the Northern and Southern hemisphere winters—the World Health Organization makes its best guess about the strains likely to emerge the following year. Pharmaceutical companies use the information to develop vaccines and soon begin production, typically by injecting viruses into hundreds of millions of chicken eggs where they grow for a few days before extraction. After several weeks of further processing, in late summer manufacturers send the flu shots to clinics and pharmacies for distribution to patients throughout the fall.