In general, the vaccine can be administered during menstruation and will not affect the effectiveness of the vaccine or the menstrual cycle. However, women who are menstruating are usually weak and may suffer from discomfort such as back pain, weakness and abdominal pain. Therefore, if not necessary, it is recommended that the vaccine be administered during non-menstrual periods as much as possible to avoid any adverse reactions to the vaccine combined with the discomfort of menstruation itself, which may cause an increased burden on the body. Vaccines are foreign substances and may cause adverse reactions when they enter the body. If a menstruating woman is allergic or has symptoms such as fever, inflammation, or diarrhea, vaccination is even less recommended to avoid aggravation of the condition or other serious symptoms. After vaccination, redness, swelling and pain at the injection site, as well as symptoms such as weakness, mild rash and low fever may occur, which are usually normal and may resolve on their own. If a woman is allergic to the vaccine components, she may develop symptoms such as high fever, vomiting, fainting, drowsiness, hematuria, allergic rash, angioneurotic edema, anaphylaxis, toxic shock, etc., which require immediate resuscitation treatment and prompt hospital consultation and active treatment to avoid aggravation of symptoms or life-threatening conditions.