Both the quadrivalent and the nine-valent are worthwhile. Although the nine-valent HPV vaccine offers a wide range of preventive benefits, there is an age restriction of <26 years and it is relatively difficult to purchase, so it will depend on the age of the person receiving the vaccine and the extent of the preventive benefits. Both the quadrivalent and the nine-valent are used to prevent HPV infections. While the vaccine protects against the widest range of viruses, there is an age restriction for the HPV vaccine. Quadrivalent vaccine its vaccination age range is 9-45 years old women, can prevent HPV6, HPV11 and HPV16, HPV18 HPV infection. Nine-valent vaccine is applicable to people whose age range is limited to 16-26 years old, and it can prevent the infection of nine subtypes of HPV viruses, including HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58, etc., and it has a high prevention rate. If you are of age, you can get the nine-valent vaccine, and if you are over age, you can get the quadrivalent vaccine. However, the nine-valent vaccine is very difficult to buy at present, so you can also get the quadrivalent vaccine first for prevention.