Moderna is developing a single vaccine that combines a booster dose against COVID-19 with its experimental flu shot.
The company hopes to eventually add vaccines it is working on for respiratory syncytial virus (RSV) and other respiratory diseases as an annual shot.
"We believe this is a very large opportunity that is ahead of us, if we could bring to market a high-efficacy pan-respiratory annual booster," Moderna chief executive Stephane Bancel said during a presentation to update investors on its drugs in development.
"We believe Moderna could be first to market in this important new opportunity," he said on Thursday.
The company is conducting clinical trials for an RSV vaccine in older adults.
Moderna and Pfizer and German vaccine partner BioNTech SE are already expected to reap billions of dollars from COVID-19 booster shots, analysts and healthcare investors say.
Adding influenza and other diseases could further boost those profits.
The drug maker already had several influenza vaccine candidates in development. The new vaccine combines the experimental flu shot that is furthest along with its COVID-19 vaccine.
Novavax, which does not yet have US authorisation for its COVID-19 vaccine, said on Wednesday it has initiated an early-stage study to test its combined flu and COVID-19 shots.
Moderna also provided updates on its ongoing mid-stage trial testing its authorised COVID-19 vaccine in children aged six months to 11 years old. It is testing a 50-microgram dose of the shot in the pediatric trial involving 4000 children.
Moderna's vaccine, which received an emergency use authorisation for two 100-microgram doses for people aged 18 and older in the United States in December, is currently under an FDA review for use in adolescents.
The Pfizer/BioNTech vaccine was authorised for those aged 12 to 15 earlier this year.