Recently both Pfizer and Moderna announced they were developing a combination injection utilizing mRNA coding for the BA4/BA5 Omicron subvariant and new mRNA coding for antigens contained in the influenza virus.[i] 
Because the COVID-19 component is under Emergency Use Authorization, has failed animal data and no human studies, that component should be off the table from the start.
A recent paper from Chemaitelly and colleagues demonstrated in the Omicron era, COVID-19 boosters had unacceptably low protection against acquiring the infection and no valid study has ever demonstrated reductions in hospitalizations and deaths.[ii]  To make matters worse, any theoretical benefit from a COVID-19 vaccine would last < 6 months, so additional shots would be out of phase with the other component of the combination product….