Influenza vaccine - WikipediaAU: S4 (Prescription only)[1][2][4][5][6] CA: ℞-only / Schedule D[7][8][9][10][11] UK: POM (Prescription only) US: ℞-only EU: Rx-only[12] In general: ℞ (Prescription only) Influenza vaccines, colloquially known as flu shots, are vaccines that protect against infection by influenza viruses.[13][14] New versions of the vaccines are developed twice a year, as the influenza virus rapidly changes.[13]
