In November, the Walter Reed [Army Institute of Research] vaccine -- which would provide immunity against several different coronaviruses -- completed phase 1 human trials [n=29 after exclusions], marking an important step forward. Unlike the mRNA vaccines developed at warp speed to combat Covid-19, universal coronavirus vaccines remain several years away from distribution.

reference
C-SPAN | Universal Flu Vaccine Milkin Institute panel, 2019
feat. Fauci
Warren offers infectious-disease plan amid China outbreak 2020
"including a universal immunization against the flu ... to increase NIH funding by $100 billion"

archived living lab Thu Jan 30th, 2020