Influenza is not contagious when it is completely cured, but it is possible to be re-infected with other subtypes of influenza. Influenza refers to influenza, which is a disease caused by influenza virus infection with fever, weakness and muscle aches as the main clinical manifestations. After the flu is completely cured, the influenza virus carried by the body will be completely eliminated and antibodies to the influenza virus will be produced. At this time, the body is no longer able to eliminate the influenza virus, so it is not contagious, and will not be infected even if it comes into contact with it. After the flu is completely cured, the antibodies produced by the body are not effective against all subtypes of influenza viruses, but only against specific subtypes, and the titer of influenza virus antibodies will decrease over time, so there is a possibility of being re-infected or infected with other subtypes.