The HPV vaccine does not affect the effectiveness of the vaccine during menstruation. The HPV vaccine can be given during menstruation, but it is best if you can avoid menstruation. The main reason is that some people experience discomfort during menstruation, such as discomfort in the lower abdomen or gastrointestinal reactions such as nausea, vomiting, diarrhea, etc. Some people may also have a fever or other reactions. If HPV vaccine is administered during this period, some adverse reactions may occur, such as fever, gastrointestinal discomfort, nausea, vomiting, etc. If you get the HPV vaccine during your menstrual period and experience these discomforts, it is not possible to tell whether they are caused by the HPV vaccine or by menstruation itself, so it is best if you can avoid menstruation. Of course, people who have never experienced any discomfort during their menstrual period can also get the HPV vaccine during their period.