Methods and compositions (such as pharmaceutical compositions) for treating influenza virus type A infections in human subjects include PAR2 agonists being administered to the subject. The PAR2 agonists include small organic molecules, antibodies, and aptamers. In addition, the PAR2 agonist may be a PAR2 activating peptide. Exemplary PAR2 activating peptides include SLIGRL (SEQ ID NO: 1) and SLIGKV (SEQ ID NO: 2).