▎ WuXi AppTec content team editor
Cervical cancer is the fourth most common cancer among women worldwide in terms of new and fatalities. In 2020, there were more than 600,000 new cases of cervical cancer worldwide, resulting in more than 340,000 deaths in women, accounting for 6.5% and 7.7% of new cancer and cancer deaths in women, respectively.
At the same time, cervical cancer is also the cancer that is most likely to be eliminated by humans. In November 2020, under a call led by the World Health Organization, 194 countries around the world committed for the first time to eliminate cervical cancer. Human papillomavirus (HPV) vaccination, efficient screening for cervical cancer and effective treatment will be one of the three key measures.
At present, a number of HPV vaccines in China have been approved for marketing by the State Drug Administration (NMPA). Recently, another HPV vaccine, the bivalent human papillomavirus vaccine (Bichi Yeast, trade name: Wolzehui), was approved for marketing, mainly for the prevention of cervical cancer and precancerous lesions caused by human HPV16 and 18 infections, including pre-filled syringes and vials.
Screenshot source: NMPA official website
According to public information, the vaccine is suitable for women aged 9-30 years, the immunization program is 3 doses (0, 2, 6 months), and 9-14 years old women can also use 2 injections (0, 6 months).
About HPV
HPV is a class of unencapsulated double-stranded cyclic DNA viruses that have a fondness for the epidermis or mucosal squamous epithelium – "the virus has a fondness for certain parts" can be simply understood as being more likely to invade these sites, causing infection and leading to disease.
HPV infections are common, and almost all men and women will be infected with at least one type of HPV at some point in their lives, resulting in long warts on the skin or mucous membranes.
However, more than 90% of HPV infections can be cleared by their own immune system, and only a small proportion of the population cannot be cleared and cause persistent infections, and even multiple types of cross-infection, resulting in cancer and precancerous lesions. Among them, the most well-known is cervical cancer, and other types of cancer include oropharyngeal cancer, vulvar cancer, vaginal cancer, penile cancer and anal cancer.
Taking cervical cancer as an example, about 70%-75% of cervical cancer and 40%-60% of cervical precancerous lesions worldwide are caused by HPV16 and 18 infections.
Image credit: 123RF
About hpv vaccine
The HPV vaccine is the world's first vaccine to be used to prevent tumors, and it is the first attempt by humans to eliminate a cancer through a vaccine. This vaccine uses a special protein shell on the virus to trigger the body's immunity.
Publicly available information shows that the HPV vaccine was first approved for use in women aged 9-26 years in 2006 to prevent hpv infection and the development of precancerous lesions of the cervix. At present, there are two(b), quadrivalent and nine-valent types of HPV vaccines available in China and globally.
"Valence" represents the type of virus that the vaccine can prevent. Bivalent vaccines can prevent HPV16 and 18 infections; quadrivalent vaccines can prevent HPV6, 11, 16, and 18 infections; and nine-valent vaccines can prevent HPV6, 11, 16, 18, 31, 33, 45, 52, 58 infections.
According to the World Health Organization, 90% of girls should complete HPV vaccination by the age of 15.
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About bivalent HPV vaccine (Pichizaces cerevisiae)
According to public information, the bivalent human papillomavirus vaccine (Pichiella) approved for marketing this time is produced by the Pichi yeast expression system and has many advantages. For example: 1) the yeast expression level is high, which is conducive to separation and purification; 2) the expression can be strictly controlled; 3) the expression product is stable.
In April 2020, the HPV vaccine completed Phase 3 clinical studies and received clinical trial reports.
1) Cervical cancer;
2) Grade 2 and Grade 3 cervical intraepithelial neoplasia and adenocarcinoma in situ;
3) Persistent infection caused by HPV16 and 18 types.
Image credit: 123RF
All in all, HPV vaccination is an important means of cervical cancer prevention. Thanks to the promotion of vaccines, the incidence of cervical cancer has slowly and steadily declined, and the benefits for young women are particularly obvious.
We expect that with the approval of this HPV vaccine, it will bring more vaccination options to people and prevent the occurrence of related infections and cancers.