For the 2024–2025 flu season, all nasal spray influenza (flu) vaccines are designed to protect against three influenza viruses. These viruses contained in the vaccine include an influenza A (H1N1) virus, an influenza A(H3N2) virus, and one influenza B virus.For the 2024–2025 flu season, all nasal spray influenza (flu) vaccines are designed to protect against three influenza viruses. These viruses contained in the vaccine include an influenza A (H1N1) virus, an influenza A(H3N2) virus, and one influenza B virus.