Human papillomavirus, or HPV, can be injected with the HPV vaccine just after menstruation. 1. Since most people may experience varying degrees of effects from the HPV vaccine when they are menstruating, it is generally recommended that the HPV vaccine be given after the menstrual period has passed, and that the HPV vaccine can be given just after menstruation, i.e., when the menstrual period has ended. 2. Although it has not been proven that HPV can adversely affect women during pregnancy and the fetus as well as whether it is secreted through breast milk during breastfeeding, it is best to wait until the end of breastfeeding and the end of pregnancy before receiving the HPV vaccine. 3. If you experience irregular menstruation after HPV vaccination, do not be overly nervous or worried, as it will usually recover on its own after a period of time. Adverse reactions such as headache, nausea and rapid heart rate may also occur after HPV vaccination, so pay attention to rest, drink plenty of water, and go to the hospital in time for examination and treatment if the symptoms are not relieved.