Updated publication reference for PubMed record(s): 31797923. We combined metabolic pulse labeling and quantitative shotgun proteomics to globally monitor protein synthesis upon infection of human cells with a human- and a bird-adapted IAV strain. While production of host proteins was remarkably similar, we observed striking differences in the kinetics of viral protein synthesis over the course of infection. Most importantly, the matrix protein M1 was inefficiently produced by the bird-adapted strain at later stages.