Can an influenza virus carry other infectors with it?
I wouldn't call influenza a vector here, but yes, an infection with the flu virus which results in a full infection can have secondary infections as complications. There are often caused by bacteria which usually live in the respiratory pathway and kept under control by the immune system.

This includes pneumonia (either viral or bacterial), inflammation of muscles and the heart muscle (myositis and myocarditis) as well as pericarditis. Less severe complications include infections like ear infections and sinusitis.

See the references for more details:

References:


Complications of Viral Influenza
Double trouble: Bacterial super-infection after the flu
A Mouse Model of Lethal Synergism Between Influenza Virus and
Haemophilus influenzae