A single dose is less expensive, less resource-intensive, and easier to administer.
Written by | Tian Dongliang
Source | "Medical Community" public account
From 4 April to 7 April, the World Health Organization's Strategic Advisory Group of Experts on Immunization (SAGE) met to review the evidence for 1 dose of human papillomavirus (HPV) vaccination and concluded that a single dose of HPV vaccine provides reliable protection and is comparable to the efficacy of 2 or 3 doses of vaccination regimens.
WHO Assistant Director-General Nothemba Simelela said a single dose is less costly, takes up fewer resources and is easier to administer. It also makes re-vaccination campaigns for different age groups easier, reduces the challenge of having to follow up and manage multiple vaccinations, and saves health money and human resources that can be used for other health priorities.
SAGE recommends the following immunization procedures: 1 dose or 2 doses for women aged 9-14 years (the highest priority population), 1 dose or 2 doses for women aged 15-20 years, and 2 doses for women over 21 years of age (6 months apart).
Among female malignancies, the incidence of cervical cancer is second only to breast cancer, most cervical cancer is caused by HPV virus infection, and cervical cancer is also one of the few cancers that can be effectively prevented by HPV vaccination.
Human papillomavirus is a common virus in nature, and more than 130 species have been isolated so far, and different types produce different clinical manifestations:
HPV 1, 2, 3, 4, 7, 10, 12, 15, etc. and common warts, flat warts, plantar warts, etc.;
HPV 5, 8, 14, 17, 20, 36, 38 is associated with verrucous epidermal dysplasia;
HPV-6, 11, 13, 32, 34, 40, 42, 43, 44, 54, etc. are related to genital,, oropharyngeal, and esophageal mucosal infections;
HPV-16, 18, 30, 31, 33, 35, 39, 53 and cervical cancer, rectal cancer, oral cancer, tonsillar cancer and other related.
The causes most closely related to cervical cancer are HPV16 and 18, of which the HPV16 subtype has the greatest potential to induce cancer.
According to a popular science article on HPV vaccination on the official website of Myoyou Medical International, HPV vaccination is generally recommended for boys and girls aged 11 to 12 years, and the vaccination time can be advanced to 9 years old, and it is best to be vaccinated before sexual contact and exposure to human papillomavirus. Theoretically, hpv vaccination of boys could also reduce transmission rates, thereby protecting girls from the virus. Certain types of HPV are also associated with cancers of the mouth and throat, so the HPV vaccine can also provide protection against such cancers.
Liu Jie, deputy chief physician of the Department of Obstetrics and Gynecology of Shanghai Tenth People's Hospital, pointed out in a related popular science article that there are currently two-valent, quadrivalent and nine-valent HPV vaccines that can be vaccinated in the mainland. The types of prevention, the effect of prevention, and the appropriate population of the three vaccines are detailed in the following figure:
As can be seen from the chart, the current HPV vaccine administered in the mainland is 3 doses.
A research report on the domestic HPV vaccine market space released in early 2022 shows that the number of women aged 9-45 in China is about 381 million, and the current penetration rate of HPV vaccination among women of appropriate age is only about 7%. The willingness of mainland women to get HPV vaccines at their own expense is very high, and so far, quadrivalent and nine-valent HPV vaccines in many regions are still in short supply.
In November 2020, the WHO officially launched the "Global Strategy to Accelerate the Elimination of Cervical Cancer", which was committed by 194 countries around the world, and China also responded to the CALL of the WHO, and the National Health Commission plans to launch pilots in 15 cities to promote the application of HPV vaccines. At present, Many provinces and cities such as Xiamen in Fujian, Ordos in Inner Mongolia, Jinan in Shandong, Guangdong Province, Chengdu in Sichuan, and Wuxi in Jiangsu have introduced corresponding policies to give free HPV vaccination to women of appropriate age.
Source: Medical community
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