An Overview of HPV Vaccines
Posted on: 14 November 2020 by chen shanshan
An Overview of HPV Vaccines
HPV vaccine is used to prevent HPV virus infection. In addition to preventing cervical cancer, it can also prevent genital warts and other diseases caused by HPV infection. There are currently three types of HPV vaccines that benefit more than 100 countries and regions around the world: 2-valent, 4-valent and 9-valent vaccines. The 2-valent vaccine can prevent 70% of cervical cancer; 4-valent vaccine can prevent 70% of cervical cancer, as well as vaginal cancer, vulvar cancer, and genital warts; 9-valent vaccine can prevent 90% of cervical cancer, 85% of vaginal cancer, and 95% of anal cancer. Male friends can also be vaccinated with 4-valent and 9-valent vaccines to prevent genital warts and other diseases.
Should HPV vaccine be given and when is it appropriate?
The incidence of cervical cancer ranks highly among female genital malignant tumors. Therefore, the introduction of HPV vaccination while carrying out the cervical cancer screening project will help to significantly reduce the incidence of cervical cancer and precancerous lesions.
Girls who are 9-25 years old and have not had sex are best vaccinated. The World Health Organization recommends that the HPV vaccine is mainly targeted for girls 9-13 years old before having sex for the first time. The secondary target population is 16-26 year old women, and the voluntary vaccination population is 9-45 year old women.
The HPV vaccine has the greatest protective effect on people who have not been infected with the HPV virus. There is still a certain protective effect on people who have been temporarily infected with HPV virus, but the effect on people who are HPV positive is unknown. Therefore, women who are married, have children, and have sex can also be vaccinated against cervical cancer.
It should be noted that people who are allergic to vaccines or yeast, and pregnant women cannot get HPV vaccine.
The safety of vaccine
The world’s first HPV vaccine was launched in 2006 and has been used by hundreds of millions of people in more than 140 countries. A few developed countries have included it in the immunization program. Global HPV vaccine safety monitoring data after the market has shown that adverse reactions are usually mild and self-limiting. No serious safety problems have been found for HPV vaccines, and no vaccine-specific deaths and teratogenic cases have been found. Local adverse reactions of HPV vaccine include pain, swelling, erythema, itching, etc., and systemic symptoms include headache, fever, and nausea. Adverse reactions are mainly mild and severe are rare. Adverse reactions can disappear within 5-14 days.
How is the potency
Judging from the current application situation, there is no need to supplement the vaccine after the injection to boost immunity. According to the results of the follow-up, the protective effect of the vaccine lasts for at least ten years, theoretically for 30 years.
Therapeutic HPV Vaccines
In contrast to the prophylactic vaccines, the development of new therapeutic vaccines is focused on targeting E6 and E7. Effector T cell responses to these viral, non-self oncoproteins, which are constitutively expressed by transformed cells, are likely to play a role in mediating lesion regression. Persons with preinvasive disease present an unparalleled opportunity to determine proof-of-principle for immunotherapeutic strategies. These lesions are directly accessible and clinically indolent, providing an opportunity to assess the relevant tissue before and after intervention. Moreover, a subset of patients does respond, thereby making it possible to determine either pretreatment characteristics that predict therapeutic effect, or characteristics of induced immune responses that predict therapeutic benefit. Tissue studies will also afford the ability to determine mechanisms of immune suppression mediated by different stages of HPV disease. Several vaccine platforms have been evaluated, including naked DNA; DNA administered with electroporation; viral vectors, including modified vaccinia Ankara (MVA) and vaccinia virus; peptides administered with adjuvant; and bacterial constructs, such as Listeria monocytogenes.