Highlights•Host immune responses play both protective and pathogenic roles in IAV and
CoV infections.•Synergy of adaptive and innate immunity is required for efficient control of
virus infection.•Novel strategies are needed to suppress immunoevasion and to improve
antiviral effects.•Vaccine-mediated protection could be improved by optimizing immune
responses.•Understanding co-evolution of host and virus is key to predicting viral mutation
and transmission.Respiratory viruses, especially influenza A viruses and coronaviruses …