HPV infection causes a lot of suffering to patients. So, is there a vaccine for HPV? What kind of vaccine is available? How effective is it? Is it safe? Who can get it? Where can I play it? 1. What kinds of HPV vaccines are there? HPV vaccines can be divided into three types according to their effects. The first is a preventive vaccine, which prevents HPV infection, mainly by inducing humoral immunity, and is administered to young women before they become infected with HPV, and is not effective for women who are already infected with HPV or have cervical precancer and cervical cancer. The second is a therapeutic vaccine, which can play a therapeutic role by inducing both cellular and humoral immunity, and is used to treat patients who are already infected with HPV or have existing cervical lesions. The third type is a vaccine that can be used for both prophylactic and therapeutic purposes. Currently, therapeutic vaccines and vaccines with both preventive and therapeutic effects are still in the development stage, while preventive HPV vaccines are already available. A new generation of prophylactic HPV vaccines is also under development, giving HPV vaccines the ability to cover a wider range of HPV subtypes. It also has the advantages of being relatively inexpensive and easy to produce, which is of practical significance for developing countries. 2.What are the vaccines that have been marketed for use so far? Currently, two HPV vaccines are widely used worldwide: the quadrivalent vaccine Gardasil (anti-HPV-6, 11, 16, 18) from Merck in the United States and the bivalent vaccine Cervarix (anti-HPV-16, 18) from GlaxoSmithKline in the United Kingdom, which were approved for marketing in the United States and Australia in 2006 and 2007, respectively. Since then, the vaccines have been licensed in more than 100 countries worldwide. Merck’s quadrivalent vaccine Gardasil protects against both cervical cancer and precancerous lesions of the cervix, vulva and vagina caused by HPV 16 and 18, as well as other cervical, vulvar and vaginal lesions, including genital warts, caused by the four HPV subtypes mentioned above. The Gardasil vaccine is a sterile suspension injection administered by intramuscular injection into the deltoid region of the upper arm at months 0, 2, and 6, respectively. The Cervarix vaccine was also administered by intramuscular injection in the deltoid region of the upper arm in three doses at months 0, 1 and 6. 3.How effective is the prophylactic HPV vaccine in preventing cervical cancer? Prophylactic HPV vaccination can reduce the incidence of CIN by 95% and the incidence of CIN II-III and carcinoma in situ by 67%, which proves that HPV vaccine can significantly reduce the incidence of CIN and cervical cancer. 4.How safe is the prophylactic HPV vaccine? Prophylactic vaccine, because it is used for young and healthy individuals, most of whom do not necessarily develop cervical cancer due to HPV infection even if they do not use the vaccine; therefore, the safety of this type of vaccine is the most important. So is the use of this type of vaccine safe? Foreign studies have shown that some toxic side effects have occurred in some people after vaccination, but 94% are considered to be non-serious, including injection site pain, headache, fever, rash, dizziness, syncope, nausea, etc. Only 6% are considered to be serious adverse events, including Green-Barre syndrome, venous thromboembolism and death, but there is no obvious causal link between the above serious adverse events and HPV vaccine. In addition, there is no evidence-based medical evidence that HPV vaccine increases the incidence of related diseases. In addition, for the vaccine to be widely available, it must be suitable for developing countries with relatively weak technical resources, and the vaccine’s affordability, efficacy, and prevention effects that can last for a longer period of time and significantly reduce the incidence of cervical cancer and mortality need to be taken into account. 5. What is the population for which HPV vaccine is indicated? The most important target groups for prophylactic HPV vaccine are school-age children and adolescents, and the most ideal period for vaccination is before first sexual intercourse and before HPV exposure. However, vaccination of this population can be difficult because parents may perceive the vaccine as detrimental to their health. The recommended age for vaccination varies by country and region. Both vaccines can be used in females aged 9-12 years. Among females aged 13-26 years, it is recommended that those who have never been vaccinated should be vaccinated. Because the vaccine is most effective in preventing genital warts in people who are not sexually active, the HPV vaccine is also indicated for the prevention of genital warts in men aged 9-26 years, in addition to women in this age group. Since 30% of cervical cancers are not caused by HPV 16/18 but by other HPV high-risk subtypes, routine cervical cancer screening should continue for women who have received the HPV vaccine. In the United States, the vaccine is not recommended for women older than 26 years of age. 6. What other problems exist in the use of HPV vaccine? It is undesirable to be overly confident that vaccination will protect you from HPV infection or cervical cancer, so instead you will engage in higher-risk sexual activity and neglect regular checkups. This is because the duration of protection from any one vaccine is limited and the HPV vaccine does not protect against all types of HPV subtypes of infection. The difficulties in discussing sexual behavior and STDs with most adolescents and their parents in general due to multiple sociocultural factors make it even less easy for the general population to receive preventive vaccination promotion. The current high price of the HPV vaccine affects its widespread use, especially in developing countries. Some foreign experts have compared the cost-effectiveness analysis of vaccine alone, screening alone and vaccine plus screening, and proposed that combining the vaccine with cervical cytology screening is the most economical method. Specifically, vaccination should be started at the age of 24 and screening should be done every 2 years. 7. Is there any HPV vaccine available in mainland China? The two vaccines mentioned above are not yet available in mainland China and are still in the clinical trial stage, while several HPV vaccines developed by domestic manufacturers are under development. The two vaccines are available in Hong Kong and Taiwan.