Everything you want to know about HPV vaccine is here.

With the popularization of HPV vaccine knowledge, many people want to be vaccinated with HPV vaccine. But how much do you know about HPV vaccine? What is the difference in the applicable population of HPV vaccines with different "prices"? In this regard, Chen Shouzhen, deputy director of the Obstetrics and Gynecology Hospital affiliated to Fudan University, summed up ten common questions and answered them to the majority of netizens.

What is HPV virus?

Human papillomavirus (HPV) is a small double-stranded DNA virus, so it is called human papillomavirus because it only infects humans. There are more than 200 subtypes of HPV, which can be divided into high-risk type and low-risk type according to whether they are carcinogenic or not.

Low-risk type usually infects the skin and causes warts, commonly known as boils. Most of them can naturally subside in 3-5 years, and some may need laser, freezing and other methods to remove them.

There are about 15 HPV subtypes (HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73 and 82) that can cause malignant tumors such as cervical cancer, vaginal cancer and oropharyngeal cancer, so they are called high-risk HPV. Among them, HPV16/18 has the highest risk of cancer. About 70% of cervical cancer in the world is caused by high-risk HPV16 and 18, and 20% is caused by HPV31, 33, 45, 52 and 58. HPV16 types 16 and 18 are also associated with oropharyngeal cancer, vulvar cancer, vaginal cancer, penile cancer and anal cancer.

Will HPV infection definitely lead to cancer?

Persistent infection of high-risk HPV will lead to cancer. More than 90% of HPV infections usually subside naturally within 2 years. If carcinogenic HPV infection lasts for more than 1 year, the possibility of precancerous or cancerous lesions will increase, but not all persistent infections will progress. Only less than 1% of infections will develop into cancer after 5 to 10 years of precancerous lesions. Therefore, even if there is HPV infection, it will not necessarily become cancer, but we should pay attention to the corresponding screening.

At present, there is no specific drug to treat HPV. Through regular screening, we can observe the situation of HPV infection, so that we can treat it at an appropriate time and reduce the risk of cancer.

Personal life is very healthy, how can you be infected with HPV?

HPV virus spreads in various ways.

It can be widely spread among people through skin contact, and more than 80% of women have been infected with HPV at least once in their lives. Sexual life is the main reason why HPV spreads around the anus and genitals. Sticking to the correct use of condoms can reduce the risk of HPV infection.

Generally speaking, there are many ways of HPV infection. At present, there is no good way to prevent HPV infection, but healthy living habits, such as quitting smoking and drinking, and wiping separately after going to the toilet may reduce the probability of HPV infection. Even if you are infected with HPV, you don’t have to be nervous, because most HPV infections can be monitored regularly after infection, and generally will naturally fade away soon.

How to prevent HPV transmission?

Vaccination with HPV vaccine can safely prevent cancer caused by persistent HPV infection.

Vaccination with tetravalent or nonavalent HPV vaccine can also prevent condyloma acuminatum, which is a benign disease, but the treatment failure rate is relatively high, affecting physical and mental health. Therefore, for the majority of women, it is very necessary to vaccinate HPV vaccine.

How to choose HPV vaccine?

At present, three different vaccines have been developed, which are divided into bivalent, tetravalent and nonavalent vaccines according to the number of HPV subtypes they target. Simply put, bivalent HPV vaccine is aimed at HPV types 16 and 18; The tetravalent HPV vaccine is aimed at HPV6, 11, 16 and 18; The nine-valent HPV vaccine not only targets the same HPV subtype as the four-valent vaccine, but also targets types 31, 33, 45, 52 and 58. At present, HPV vaccines are all preventive vaccines, aiming at preventing initial HPV infection and subsequent HPV-related diseases.

At present, many hospitals, from community medical service centers to tertiary hospitals, have HPV vaccines, and these HPV vaccines can be safely vaccinated. Because of limited resources, the queue time of nine-valent vaccine will be longer. If resources and funds are not a problem, it is recommended to vaccinate the nine-valent HPV vaccine. If there is no nine-valent HPV vaccine, tetravalent HPV vaccine and bivalent HPV vaccine are also good choices, because both vaccines cover the most dangerous types 16 and 18. Generally speaking, you should try to use the same vaccine preparation to complete vaccination. However, if you don’t know the original HPV vaccine dosage form, you can also use another HPV vaccine preparation to complete the subsequent vaccination.

At what age is it appropriate to get HPV vaccine?

At present, the recommended age of HPV vaccination in China is 9-45 years old. Most countries in the world recommend routine HPV vaccination at the age of 11-12, and some suggest starting from the age of 9. For teenagers and adults aged 13-26, replanting is also recommended if they have not been vaccinated with HPV vaccine or have not completed a series of vaccines.

Why don’t foreign countries recommend routine replanting for adults over 27 years old? This is because with the increase of age, the possibility of infection with subtypes covered by HPV vaccine is gradually increasing. For older people, the benefit and cost performance of HPV vaccination are low. However, research shows that there are two peaks of high-risk infection among women in China: 17-24 years old and 40-44 years old, and single HPV infection is the main infection. Considering the characteristics of female infection and the low coverage rate of cervical cancer screening, experts suggest that women aged 9-26 should be vaccinated with HPV, and women aged 27-45 should be vaccinated when conditions permit. Women over the age of 45 don’t have to worry. At this stage, the HPV vaccine is low in cost performance, and the standardized HPV screening is enough to prevent cancer.

In the recommended age range, the best time for HPV vaccination is before the first sexual intercourse, because HPV vaccine immunization is the most effective for individuals who are not infected with HPV. That is to say, the younger you are when you are vaccinated with HPV, the more the incidence of cervical cancer decreases.

Are there any side effects of vaccination?

Vaccination of HPV vaccine, like other vaccines, may have pain, swelling and erythema at the inoculation site. A few people may have syncope or dizziness, and there are some rare other side effects, which may be related to the adjuvant in the vaccine, so you can rest assured to vaccinate. In addition, HPV vaccine can be safely inoculated in different parts with other vaccines at the same time. At present, there is evidence that inoculation of tetanus, acellular pertussis, diphtheria and inactivated polio vaccine at the same time with HPV vaccine does not damage the immune effect of the body against HPV vaccine or other vaccines at the same time.

Because there is no relevant evidence, it is generally not recommended to vaccinate HPV during pregnancy. However, with the increase of the number of people vaccinated, more and more data about unintentional vaccination after pregnancy show that vaccination during pregnancy has no effect on the safety of mother and child. Nevertheless, the remaining vaccination should be postponed, and it is best for vaccinated women to get pregnant two months after the vaccination is completed. Vaccine does not affect the safety of breastfeeding, but at present, such data are limited, so it is necessary to carefully consider HPV vaccination for lactating women.

I have been infected with HPV before, can I still be vaccinated?

There is no need to evaluate whether you have been infected with HPV before vaccination. A history of abnormal cervical cancer screening, genital warts and HPV infection is not a taboo for HPV immunization. Because these conditions all suggest that HPV was infected in the past, but it is not necessarily HPV subtype infection covered by HPV vaccine. For people who have a history of HPV infection but are still within the recommended age range, vaccination is still recommended because it still has a protective effect on the uninfected vaccine strain HPV virus. However, for people who have been infected with the subtype covered by HPV vaccine, the benefits of immunization are small.

What if we miss the seeds? I have been vaccinated with bivalent or tetravalent HPV vaccine before. Do I need to replant with nine-valent HPV vaccine?

Missing seeds means that immunization is not carried out according to the schedule. At present, the evidence shows that no matter how long the series vaccination is interrupted, it can continue to vaccinate without restarting the series vaccination.

Now it is found that HPV vaccine has a long-lasting protective effect against HPV-related diseases, and there is no need for multiple cropping. For women who have already completed bivalent or tetravalent HPV vaccination, the benefit of using nine-valent vaccine for multiple inoculation may not be obvious, so it is not recommended.

After vaccination with HPV vaccine, can I avoid regular screening?

At present, HPV vaccine can only prevent infection. After vaccination, existing HPV infection, genital warts or precancerous lesions cannot be eliminated, and the vaccine can only prevent cervical cancer caused by seven subtypes at most. After injection of HPV vaccine, other subtypes of HPV may still be infected, which may lead to cancer. Therefore, cervical cancer screening is still needed after HPV vaccination.