Currently, there are bivalent, quadrivalent and nine-valent vaccines approved to be marketed in China, why is it called quadrivalent vaccine? It is because the quadrivalent vaccine can protect against four types of viral infections, two high-risk types 16 and 18 and two low-risk types 6 and 11, respectively. If the quadrivalent vaccine is administered, it can theoretically prevent more than 70% of cervical cancer and 90% of genital warts. Currently, the quadrivalent vaccine is mainly given to women between the ages of 20 and 45, and the vaccination is given at 0, 2 and 6, requiring a total of three doses, which are available at disease control centers and hospitals in some cities across the country.