HPV vaccine is free in Jiangsu! Here are some things you need to know about HPV

Recently, there is good news. On December 21, an eighth-grade student in Lianyungang became the first girl in Jiangsu Province to receive free HPV vaccination.

It is understood that Jiangsu has released the "14th Five-Year Plan" for the development of women and children, encouraging areas with conditions to promote HPV vaccination with a focus on school girls aged 9-15. This Lianyungang pilot project is aimed at eighth-grade girls in Lianyun District, providing them with two doses of domestically produced bivalent HPV vaccines for free. Previously, free HPV vaccination has been implemented in Ordos, Inner Mongolia, Xiamen, Fujian, Jinan, Shandong and other places.

Currently, there are domestically produced bivalent, imported bivalent, quadrivalent, and nonavalent HPV vaccines on the market. Does the higher the "valence" of the vaccine, the better the effect? ​​What is the best age to get vaccinated? Does the vaccine solve the problem once and for all? This issue of NetEase Health's "Health Concerns" column will reveal the answers for you.

First, we must understand the HPV "family"

HPV (Human Papilloma Virus) is the full name of human papillomavirus, which is a general term for a group of DNA viruses that infect the skin or mucous membranes. HPV is a large family, with more than 200 types discovered, about 40 types of which are related to reproductive tract infections, and some types of HPV infection are potentially carcinogenic.

Based on the biological characteristics and carcinogenic potential of HPV, it can be divided into low-risk and high-risk types.

Low-risk HPV types such as 6, 11, 42, 43, 44, etc. can cause some benign skin changes and genital warts, including common warts, plantar warts, flat warts and condyloma acuminatum, which are more common in female vulva, vagina, cervix and around anus. Among them, HPV6 and HPV11 infection are associated with the vast majority of genital condyloma acuminatum and almost all recurrent respiratory papilloma.

High-risk HPV types such as 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68, etc. are related to cervical cancer and cervical intraepithelial neoplasia. Persistent infection with high-risk HPV in the cervix may cause cervical cancer. About 90% of cervical cancer is related to high-risk HPV infection, of which 70% of invasive cervical cancer is related to HPV16/18 infection.

Why do women need to get the HPV vaccine?

Statistics show that more than 70% of women will be infected with HPV at least once in their lifetime. HPV infection is usually seen about 2 months after a woman's first sexual intercourse, and about 60% of women are found to be infected with HPV within the next 5 years.

Of course, HPV infection does not mean cervical cancer. At the beginning, most women are infected with HPV asymptomatic transient infections, which may manifest clinically as low-grade squamous intraepithelial lesions of the cervix. In the case of good immunity, the probability of the virus being cleared by the body's own immunity is higher than 80%. However, if the infection persists, it will progress to high-grade squamous intraepithelial lesions. If the infection persists, after 8-12 years, it will evolve into cervical cancer.

How terrible is cervical cancer? Its incidence and mortality rate are ranked fourth among female cancers in the world, second only to lung cancer, breast cancer and colorectal cancer. About 570,000 people are diagnosed with cervical cancer every year in the world, and about one woman dies from it every 2 minutes. There are more than 100,000 new cases of cervical cancer in my country every year, accounting for about one-sixth of the global incidence.

99% of people who develop cervical cancer have HPV infection. On the other hand, without HPV infection, women will hardly develop cervical cancer. Therefore, it is very necessary to vaccinate women with HPV vaccine to prevent cervical cancer.

When is the “golden age” for HPV vaccination?

The clearance rate of HPV is closely related to age and the duration of virus existence. Studies have shown that the clearance rate of HPV infection decreases by 15% for every 5 years of age after first sexual intercourse. Therefore, in theory, the younger the age of HPV vaccination, the better the effect. But in fact, for girls in childhood, since they generally do not engage in sexual activity, there is no need for vaccination. So, what is the best age to get vaccinated?

The World Health Organization recommends that girls aged 9-14 be the first choice for HPV vaccination. Before having sexual intercourse, the chance of HPV infection is almost zero. HPV vaccine is used to prevent rather than treat HPV infection. Parents should arrange for their children to be vaccinated as early as possible, and it is best to complete all doses of vaccination before starting sexual intercourse.

The higher the price of HPV vaccine, the better?

At present, there are three types of HPV vaccines in China: bivalent, quadrivalent, and nonavalent. The "valence" represents the number of virus types that the vaccine can prevent. The bivalent vaccine targets two viruses, HPV16 and 18, the quadrivalent vaccine targets four viruses, HPV16, 18, 6, and 11, and the nonavalent vaccine targets nine viruses, including HPV16, 18, 6, 11, 31, 33, 45, 52, and 58.

Regarding the question of "Is the higher the price, the better?", it is not possible to generalize. From the perspective of the types of viruses that HPV vaccines prevent, the higher the price of the HPV vaccine, the more virus subtypes it prevents. However, the vaccine's preventive effect on viruses is not only determined by the number of virus types it prevents, but also by factors such as vaccine potency (that is, preventive ability) and antibody titer.

In terms of cervical cancer prevention and control, in theory, the bivalent and quadrivalent vaccines are equally effective, with protection rates of 70%, while the nine-valent vaccine has a protection rate of up to 90%. Therefore, experts believe that what is important is not the potency of the vaccine, but the ability to obtain protection through timely vaccination.

Wouldn't it be better to just get the nine-valent vaccine? Of course not! Currently, China has corresponding age requirements for different types of HPV vaccines.

The bivalent vaccine is suitable for women aged 9-45 years. The imported bivalent vaccine requires a total of 3 injections, 1 injection each at 0, 1, and 6 months, and the vaccination should be completed within 6 months. There are some minor changes in the vaccination procedure for the domestic bivalent vaccine. The vaccination procedure for children aged 15-45 is the same as the imported bivalent vaccine, but children aged 9-14 years only need to receive 1 injection each at 0 and 6 months.

The quadrivalent vaccine is suitable for women aged 20-45, and the nine-valent vaccine is suitable for women aged 16-26. The quadrivalent and nine-valent vaccine procedures are the same, requiring a total of three injections, one at 0, 2, and 6 months.

For parents with daughters, they can choose to vaccinate with different types of HPV vaccines according to their children's age, economic status and the availability of local vaccines. It is important to emphasize that if the vaccination time exceeds the specified age range, the vaccination agency will not vaccinate, so the vaccination must be done within the specified age range (calculated in years).

Like other vaccines, HPV vaccines are mainly administered in community hospitals or community health service centers, or in qualified private medical institutions. You can check online or by calling the local CDC, 12320, or other official platforms.

Does the HPV vaccine have side effects? Can the vaccine cure all diseases?

HPV vaccines are specially inactivated, so they are safe and effective, but like all vaccine injections, there are some side effects.

Some people may feel dizzy and uncomfortable when they are injected, so it is generally recommended to rest and observe for about half an hour after the injection. If there is no obvious discomfort, you can leave. There may be small redness, swelling, and nodules at the injection site, which are generally mild. Some people may also have low fever, body aches, and other similar symptoms, which can generally be relieved by themselves.

In addition, HPV vaccination is by no means a death-free gold medal and cannot provide 100% protection. Because the prevention and control system of cervical cancer is divided into three levels, the diagnosis and treatment of cervical cancer belongs to the third level of prevention and control, the screening of cervical cancer and the treatment of precancerous lesions belong to the second level of prevention and control, and the HPV vaccination belongs to the first level of prevention and control. Just because the first line of defense seems to be good, the second line of defense cannot be withdrawn. Therefore, even if you are vaccinated, you must follow the formal screening strategy and undergo regular screening.

Experts guiding this article: Tan Xianjie, doctor of medicine, professor, doctoral supervisor, chief physician of obstetrics and gynecology department of Peking Union Medical College Hospital. He has been engaged in the diagnosis and treatment of benign and malignant gynecological tumors for a long time, and is also the vice chairman of the Youth Committee of the Gynecological Oncology Branch of the Chinese Medical Association.

References:

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2. Smith JS, Lindsay L, Hoots B, et al． Human papillomavirus type dis-tribution in invasive cervical cancer and high-grade cervical le-sions: A meta-analysis update［J］． Int Cancer, 2007(121): 621-632．

3. De Vincenzo R, Conte C, Ricci C, et al. Long-term efficacy and safety of human papillomavirus vaccination［J］． Int J Womens Health, 2014(6): 999-1010.

4.Ma B, Maraj B, Tran NP, et al． Emerging human papillomavirus vaccines［J］． Expert Opin Emerg Drugs, 2012(17): 469-492.