The main differences between influenza A and influenza B are as follows.
Different pathogens: Influenza A is caused by the influenza A virus, which is more contagious and presents a violent and widespread epidemic, and the virus is more prone to mutation; Influenza B is caused by the influenza B virus and is mostly a limited epidemic.
Different degrees of symptoms: Both have fever, chills, generalised muscle aches, weakness, headache and dizziness, but influenza A is more severe.
Treatment differs: anti-influenza virus treatment (e.g. oseltamivir, paramivir, etc.) is the mainstay for influenza A and influenza B, but amantadine is only used for influenza A.