Bivalent and quadrivalent generally refer to the HPV vaccine bivalent HPV vaccine and quadrivalent HPV vaccine, there is no need to take quadrivalent vaccine for bivalent HPV vaccine. HPV is divided into two categories: high-risk virus and low-risk virus. High-risk HPV virus is a factor that triggers cervical cancer in women, while low-risk HPV virus mainly triggers condyloma acuminatum, and the HPV vaccine is used to prevent the infection of the relevant HPV viruses, so as to reduce the prevalence of cervical cancer. The bivalent and quadrivalent are both designed to prevent cervical cancers caused by 16 and 18 positives, which account for 70% of cervical cancers, which means that both the bivalent and quadrivalent are the same after vaccination and can prevent 70% of cervical cancers. Quadrivalent has two more low-risk ones, 6 and 11, which are mainly for the prevention of sexually transmitted diseases (STDs). Already received the HPV bivalent, and then inoculated with quadrivalent a bit of duplication, after playing the prevention of 16, 18 positive, so there is no need to play again. In addition, for the low-risk positive prevention of their own life pay more attention to avoid unclean sex, so there is no need to receive quadrivalent vaccine.