In recent years, there is a new reason to go to Hong Kong besides traveling and shopping, and that is to get the cervical cancer vaccine (HPV vaccine). There are more and more questions about going to Hong Kong for vaccination on various forums, and there are even enthusiastic people who have gone for vaccination sharing their experience and things to note about going to Hong Kong for vaccination on the Internet, which has received numerous positive comments. Many white-collar workers are taking advantage of their business trips to Hong Kong for vaccination. In the face of this strong fashion trend, many medical institutions in Hong Kong saw business opportunities and advertised online to attract customers, while some private hospitals in the mainland also heard the wind and moved, claiming that their vaccines were introduced from Hong Kong and could be administered at their doorsteps.
The HPV vaccine market has seen an unprecedented boom. However, there are many questions behind the explosion: Is the HPV vaccine mandatory? Is it suitable for women of any age? Is the vaccination effective for life? Why is such a good vaccine delayed in China?
HPV and HPV vaccine
HPV (Human papillomavirus), the Chinese name for human papillomavirus, is mainly transmitted sexually and can be transmitted by entering the genitals, mouth or throat during sexual intercourse or oral sex. About 170 types of HPV have been identified, and about 30 to 40 of them are transmitted sexually to the genitals and surrounding skin. Studies have found that 99.7% of cervical cancers are caused by HPV infection, and the health risk varies by type of virus.
Some types of HPV can cause genital warts, and some HPV types are associated with cellular carcinogenesis. hpv infection can cause cervical cancer, as many people already know. And indeed, these viruses can also cause other relatively uncommon cancers such as vulvar, penile, throat, lung, esophageal and anal cancers, to name a few.
Most people who become infected with HPV have almost no symptoms and do not show easily recognizable signs such as fever or localized redness and swelling. Most HPV infections also resolve on their own. HPV is the most common sexually transmitted disease, and HPV infection is inevitable during a lifetime if one is sexually active. HPV infection is so common and so unnoticeable that vaccines play a particularly important role in risk prevention.
There are currently two HPV vaccines in use worldwide, one of which is a quadrivalent vaccine developed by Merck Sharp & Dohme under the trade name “Gardasil”. It can be used against HPV types 16, 18, 6 and 11. The other is the bivalent vaccine Cervarix, developed by GlaxoSmithKline (GSK), which only targets HPV16 and HPV18 infections. Although the current vaccine does not cover all HPV virus subtypes, 70% of cervical cancers are associated with HPV16 and HPV18, while HPV6 and HPV11 may be closely related to the occurrence of warts such as condyloma acuminata. The difference between the two vaccines is that the former can be used for men in addition to women.
HPV vaccination, what should I be aware of?
The HPV vaccine was approved by the U.S. Food and Drug Administration (FDA) in June 2006, making it the world’s first vaccine to prevent cancer. In the 8 years since its launch, there have been many questions about the necessity of vaccination, vaccination age, safety, etc. The following is a brief explanation of some issues based on the guidelines published by the Centers for Disease Control and Prevention (CDC), the American College of Obstetricians and Gynecologists (ACOG), the International Federation of Gynecology and Obstetrics (FIGO), the American Academy of Pediatrics (AAP), and the Hong Kong Anti-Cancer Society.
1. Is it necessary to receive HPV vaccination?
HPV vaccination is an important tool for women to prevent cervical cancer. most people are infected with HPV during their lifetime through sexual intercourse. although most infections do not require treatment, for some women, HPV can cause changes in the cervix, which in turn can develop into cervical cancer years later, as well as potentially causing genital warts in both men and women. The use of HPV vaccines has been shown to help reduce the incidence of cervical cancer in several countries around the world, but the need for HPV vaccination for individuals also depends on factors such as age and whether or not they are infected. It is also worth noting that the HPV vaccine does not prevent all types of HPV infections.
2. When is the most appropriate time to receive the HPV vaccine?
It is generally considered that adolescent females are the preferred group for vaccination and it is best to complete the vaccination before having sexual intercourse. The American College of Obstetricians and Gynecologists (ACOG) recommends that all women between the ages of 9-26 be vaccinated, while men or women over the age of 26 do not need to be vaccinated. The CDC’s Committee on Immunization Practices (ACIP) recommends vaccination at age 11 or 12, with catch-up vaccination available for women ages 13-26 who are sexually active. The World Health Organization (WHO) recommends vaccination for 9-12 year olds. The U.S. Food and Drug Administration (FDA) has approved the HPV vaccine for ages 9-26. Overall, the recommended age of immunization varies among organizations due to differences in countries and regions and the age of first sexual intercourse.
3. Can I still get vaccinated if I am over 26 years old?
The U.S. Food and Drug Administration (FDA) and the U.S. Centers for Disease Control and Prevention (CDC) do not recommend HPV vaccination for people over 26 years of age. The main reason is not that HPV vaccination does not work in people over 26 years of age, but because of the lack of research at this stage. Past research has focused on adolescents, and studies have found that the HPV vaccine is protective in these populations. There is a lack of convincing studies for adults over the age of 26. The Hong Kong Anti-Cancer Society believes that if vaccination can still be administered over the age of 26, even if HPV infection is already present, it is rare that all subtypes corresponding to the vaccine will be infected. Overall, whether or not to vaccinate over the age of 26 depends mainly on one’s own sexual life, and if one is not yet sexually active, one can be vaccinated; for those who are married or have a regular sexual partner, vaccination is of little significance.
4. Can pregnant women receive HPV vaccine?
The HPV vaccine is an inactivated vaccine and theoretically has no adverse effect on pregnancy. Current studies have also not found adverse effects of the vaccine on pregnant women and fetuses, but guidelines from various countries recommend that pregnant women should not be vaccinated, and if pregnancy is found after vaccination, follow-up vaccination should be stopped, and other doses should be continued after delivery. And women who plan to get pregnant in Hong Kong are recommended to start pregnancy one month after the full vaccination.
5. Is HPV vaccination lifelong immunity?
Some studies have shown that the HPV vaccine still has protective effect 4-5 years after vaccination, but after all, compared with other vaccines, the vaccine has been on the market for a relatively short period of time, only 8 years, and its long-term effectiveness needs to be confirmed by long-term observation and further studies. It is important to note, however, that even women who have received the HPV vaccine are not protected against all types of HPV that cause cervical cancer. Therefore, married or sexually active women should also undergo regular cervical smear testing to detect cervical cancer and precancerous lesions as early as possible.
6. Should I be tested for HPV infection before vaccination?
Some people think that women who are sexually active should be tested for HPV infection before vaccination in order to clarify whether they should be vaccinated. The reason is that the vaccine is available to prevent multiple HPV infections, and it is highly unlikely that a woman will be infected with multiple HPV infections at the same time. Of course if the test reveals that you are indeed infected with all the types of HPV that the vaccine can prevent, then naturally there is no need for vaccination.
When will the HPV vaccine be available in China?
Eight years ago, the HPV vaccine, the world’s first vaccine that can prevent cancer, was marketed. The following year, the HPV vaccine began its journey to market in mainland China, but it has not been successful so far.
According to the current “Drug Registration Management Measures”, imported vaccines are required to conduct clinical trials before they are approved for marketing in China. In other words, for both vaccine manufacturers, whichever HPV vaccine is to enter the mainland market must first pass a clinical trial.
According to the prescribed process, each vaccine manufacturer has to submit the data to the State Food and Drug Administration after the completion of the clinical trial of the vaccine, and the Drug Evaluation Center will organize experts to review the data of the clinical trial. Those who meet the requirements will be issued with the Certificate of Registration of Imported Medicines before being allowed to import. The approval time varies depending on the specific situation and generally lasts 1-5 years.
The approval of HPV vaccine is still in progress, and the reason for the delay in approval is the different criteria for determining the indicators of vaccine effectiveness. Vaccine efficacy is the degree of reduction in disease incidence (percentage reduction in incidence) in a population after vaccination relative to a non-vaccinated population, and is a direct protective effect that can be evaluated by clinical endpoints and/or reasonable immunological (including serological) surrogates. For new vaccines, the effectiveness needs to be evaluated by clinical endpoints because the correlation between clinical effectiveness and immunological indicators has not been conclusively proven, but any protection-related immune response indicators (e.g. protection-related specific antibody titers) and clinical protection should be studied.
According to China’s Food and Drug Administration, vaccine effectiveness is measured by the amount of cancer development or cervical epithelial lesions. However, the interval from viral infection to precancerous lesions to tumors can take more than 10 years or even longer, which causes great difficulties in clinical studies. In recent years, however, there has been a growing consensus in academia that persistent infection should be used as a measure of vaccine effectiveness. In other words, if a vaccine can reduce the incidence of persistent infection, it can be concluded that it can reduce cancer risk. on April 1, 2014, WHO released the Expert Panel Report on Primary Endpoints in Preventive HPV Vaccine Trials, which recommended that persistent HPV infection in the cervix or anus for greater than or equal to 6 months be used as an alternative endpoint indicator in clinical trials to assess vaccine effectiveness.
Once the new evaluation metric is adopted by the Drug Review Center, the process of bringing the vaccine to market will be substantially accelerated. However, if the Drug Review Center does not change the current criteria, taking into account localization factors such as national ethnicity, medication habits and tolerance of drug risks, as well as the high-risk factor of the vaccine as a special drug, it will still be a long process for the HPV vaccine to be marketed in the Mainland.
In addition, the safety of the vaccine and the high price of the vaccine may also be factors that prevent the HPV vaccine from being marketed in China. HPV vaccination can cause some adverse reactions, such as localized redness and pain, as well as systemic symptoms such as fever, dizziness, and nausea. Some people also believe that the HPV vaccine has been in development for only 8 years, which is not enough time to prove its safety. In particular, the news in July 2013 that more than 30 Japanese women had pain all over their bodies after receiving the HPV vaccine and that their condition had not improved after treatment further increased concerns about the safety of the vaccine. This may also be one of the factors why China is quite cautious about the vaccine approval process. In addition to safety, the high price of the HPV vaccine is not affordable for the average person. Currently, a single HPV vaccination in Hong Kong costs about 1,000 RMB and a full vaccination costs 3,000 RMB. People who can afford the current price of this vaccine are often not the ones who need it the most. Those who never get a cervical biopsy, or who come from areas with poor sanitation, are the ones who really need the vaccine. Therefore, it is believed that even if the vaccine is released, it may not be very effective in controlling the incidence of cervical cancer in China.
In conclusion, it is important not to follow the trend of vaccination, but to do it according to your own situation, and please understand the suitability, safety and efficacy of the vaccine before vaccination. I would also like to say that vaccines alone will not work for the prevention of all diseases.