Recently, the topic #HPV vaccine three shots can only be given one shot # on the hot search, which has attracted the attention of many people who are grabbing seedlings or are planning to start vaccination.
From 4 April to 7 April 2022, WHO stated on its website that "one dose of human papillomavirus (HPV) vaccine is effective in preventing cervical cancer and is comparable to two or three doses of vaccine protection." ”
The specific content published by WHO recommends the following vaccination dose schedule for HPV:
Girls aged 9-14 years (main population) may receive one or two doses;
Young women aged 15-20 years are given one or two doses;
Two injections (6 months apart) for women over 21 years of age;
Immunocompromised individuals, including people with HIV infection, should receive three doses if feasible, or at least two doses if otherwise.
The WHO recommendation is actually aimed at addressing the low global prevalence of HPV vaccine and to vaccinating 90% of girls by the age of 15 by 2030. At the same time, it can also alleviate the global supply pressure.
So, can one dose of HPV vaccine really replace three shots? In addition to vaccinations, what other ways to prevent cervical cancer? Let's take a look.
1
What is cervical cancer?
Cervical cancer is the second most common malignancy in gynecology, and its incidence is second only to breast cancer. The high incidence age is 50-55 years old, but in recent years, there has been a trend of gradual rejuvenation, and the onset of the disease before the age of 30 years is increasingly common.
Although cervical cancer has a high fatality rate, it is the only disease with a clear cause among malignant tumors that can be prevented and screened early.
2
What does HPV have to do with cervical cancer?
HPV is a human papillomavirus that causes squamous epithelial hyperplasia of the mucous membranes of human skin. More than 96% of cervical cancer patients are infected with HPV.
At present, more than 200 different subtypes of HPV viruses have been isolated.
According to the level of risk, the subtype with high risk of carcinogenesis is called high-risk type, and the subtype with low risk of carcinogenesis is called low-risk type.
Low-risk types of HPV can cause diseases such as flat warts and genital warts. High-risk viruses can cause cervical cancer in women and penile, anal and prostate cancer in men. The most common are high-risk HPV-16 and HV-18, which account for more than 87% of the total proportion of cervical cancers. So if you are infected with the No. 16 and No. 18 HPV viruses, you must pay great attention to it.
German virologist Harald Chulhausen was the first to discover a clear causal relationship between HPV and cervical cancer, and laid the foundation for a cervical cancer vaccine that makes cervical cancer a truly preventable disease.
3
People at high risk of cervical cancer?
The most important way of HPV infection is sexual transmission, so people who have sex earlier and have more sexual partners are more likely to be infected;
In most cases, HPV can be cleared by the body's immunity and heal itself, but people with low immune function will be repeatedly infected or cause cancer; people with a family history such as cervical cancer, endometrial cancer, vaginal cancer or vulvar cancer have a higher chance of developing the disease.
For women with a sexual history of more than three years, cervical HPV virus testing should be carried out; and women should also have regular physical examinations to achieve early detection and early treatment.
4
How to effectively prevent cervical cancer?
Cervical cancer is divided into primary prevention and secondary prevention.
HPV vaccination is a first-level preventive measure for cervical cancer
HPV vaccines are divided into bivalent, quadrivalent, and nine-valent:
(1) At what age does vaccination work well?
The earlier the vaccination, the better, and before the age of 17, the risk of cervical cancer decreases by 88%. HPV vaccination is most effective for individuals who are not infected with HPV, and the best time to vaccinate is before the individual has sex for the first time.
(2) Can one injection achieve the same immune effect as three injections?
There is also a lack of strong evidence from clinical studies.
At present, all HPV vaccine instructions and guidelines or consensus in most countries mention that it is best to get 2-3 injections.
Replacing the current consensus with 1-2 needles is still needed to be supported by more clinical studies.
Cervical cancer screening is a secondary preventive measure that includes cervical TCT and HPV.
TCT test refers to the detection of liquid-based thin layer cells, which detects cervical cells and performs cytological classification diagnosis. HPV tests for viral infections, and TCT checks for abnormal changes in cervical cells. Through the combination of the two, it is really possible to achieve early detection and early diagnosis.
HPV vaccination can reduce HPV infection from the source, but HPV vaccination can not prevent the occurrence of cancer 100%, and can not prevent the progression of existing related diseases, so as long as women who have lived sexually for more than 3 years or women over 25 years old, regardless of whether they have been vaccinated against HPV, they still need to be screened for cervical cancer regularly.
5
Are there adverse reactions after HPV vaccination?
Adverse reactions after HPV vaccination are similar to other conventional vaccine adverse reactions, such as pain, swelling, erythema at the injection site, and a small number of systemic reactions such as fever, dizziness, nausea, etc., usually mild symptoms can be relieved in a short time. If you have allergies after receiving other vaccines, you should inform your doctor in advance and seek medical attention in time after an allergic reaction.
Source: Popular Science China (ID: Science_China)
Expert: Xin Deng, Peking Union Medical College, MD
Producer: Mou Yanqiu Cheng Miao Editor: Gu Peng
Proofreader: Liang Tiantian Zhang Linglin