Johnson & Johnson's vector vaccine will contribute 18.3 million doses, and a total 70 million doses of vaccines from Sanofi, Novavax and Valneva will contribute the rest.
The trial will evaluate the safety and immunogenicity of a monovalent flu vaccine candidate coding for the hemagglutinin protein of the A/H3N2 strain of the influenza virus.
"Our Phase 2 data confirm the potential of this vaccine to play a role in addressing this ongoing global public health crisis," said Thomas Triomphe, executive vice president and global head of Sanofi Pasteur.
Moderna's vaccine is based on the same messenger RNA technology that Sanofi hopes to use for its own Covid shots, after its initial efforts were called off because of disappointing trial results.