It is possible to receive the nine-valent HPV vaccine after receiving the bivalent HPV vaccine, but it is recommended that there be a gap of at least one year between doses. The HPV vaccine can be used to prevent HPV infection and can prevent diseases such as cervical cancer and vaginal cancer to a certain extent. The bivalent HPV vaccine can be used to prevent two types of high-risk HPV viruses, type 16 and type 18, while the high-risk HPV viruses prevented by the nine-valent HPV vaccine include types 6, 11, 31, 33, 45 and 52 in addition to the above types. Under normal circumstances, it is possible to receive the nine-valent HPV vaccine after receiving the bivalent HPV vaccine. However, since there is a certain buffer period for the vaccine to take effect, it is not recommended to frequently receive two HPV vaccines within a short period of time, and it is currently recommended that the interval between two vaccinations should be more than one year. For more information about HPV vaccination, consult your local CDC or community hospital.