From 4 April to 7 April 2022, the World Health Organization's Strategic Advisory Group of Experts on Immunization (SAGE) met to evaluate human Papillomavirus (HPV) vaccination data and publish vaccination data results: one dose is comparable to two or three doses of protection (Figure 1).
Figure 1 WHO releases cervical cancer vaccination results (Source: [1])
SAGE pointed out at the meeting that through a comprehensive assessment of the latest data on the efficacy of a single dose of HPV at the international level, it was found that a single dose of HPV vaccine can provide a high level of protection, and it is recommended that 1 dose or 2 doses can be given for women aged 9-14 years, 1 dose or 2 doses for women aged 15 to 20 years, 2 doses for women over 21 years of age (at 6 month intervals), and more evidence is needed for whether dose reduction doses in immunocompromised groups can provide protection. From a public health perspective, given HPV vaccine coverage, targets to eliminate cervical cancer by 2030, and the impact of the current COVID-19 pandemic on vaccination, single doses are more effective (fewer doses per cancer are needed for prevention), take up fewer resources, and are easier to implement.
While WHO has said it will consult stakeholders on these important policy changes before revising its position paper on HPV vaccination, markets are overly sensitive. In the early trading of April 14, Merck's hpv virus vaccine domestic agent Zhifei Biological (300122) fell more than 18% intraday, the first domestic bivalent HPV vaccine manufacturer Wantai Biological (603392) fell to a halt at 256.04 yuan / share, and the stock price of Watson Biological (300142), which had just been approved for the bivalent cervical cancer vaccine, fell by more than 7% at one point.
The Lancet Oncology
The protective efficacy of 1 dose of HPV vaccine is comparable to that of 3 doses
In October 2021, the International Agency for Research on Cancer (IARC) Partha Basu published a paper in The Lancet Oncology titled "Vaccine efficiency against persistent human papillomavirus (HPV) 16/18 infection at 10 years after one, two, and three doses of." Quadrivalet HPV vaccine in girs inIndia: a multicenter, prospective, cohort study" (Figure 2) [2]. The results showed that after 10 years of HPV vaccination, the protection effect of a single dose of quadrivalent HPV vaccine on high-risk HPV16 and HPV18 persistent infection was comparable to that of two or three doses of quadrivalent vaccine, reaching more than 90%.
Figure 2 Research results (Source: The Lancet Oncology)
The study, which lasted ten years, collected DATA from 17,729 HPV testing trials in Indian women who were vaccinated against HPV, from 9 Indian regions and 178 geographical clusters. Through the analysis of the data, it was found that about 70% of cervical cancers are caused by viral infections of two virus subtypes, HPV16 and HPV18, and a single dose of HPV vaccine provides no difference from two or three doses of persistent infection with HPV16/18.
The findings of The Lancet Oncology are highly consistent with WHO's HPV vaccine efficacy evaluation, and from a scientific point of view, the protective effect of one and two and three doses of HPV vaccination is comparable.
What are the HPV vaccines that can be vaccinated in China?
How we should choose
There are 3 types of HPV vaccines that have been marketed globally: bivalent, quadrivalent and nine-valent HPV vaccines. The "valence" of the vaccine refers to the type of HPV antigen contained in the vaccine, and the higher the "valence" means that the more HPV subtypes that can be prevented, the stronger the protection. The bivalent vaccine coverage types are 16 and 18, which are suitable for precancerous lesions related to 16 and 18; the quadrivalent vaccine coverage types are 6, 11, 16, 18; and the nine-valent vaccine coverage is 6, 11, 16, 18, 31, 33, 45, 52, 58. Quadrivalent and nine-valent vaccines are also suitable for cervical, vulvar, vaginal and cancers, and genital warts.
Before 2019, all HPV vaccines approved by the National Medical Products Administration (NMPA) in the mainland came from abroad, and the bivalent vaccine Xi Ruishi produced by GlaxoSmithKline in 2006 was the first HPV vaccine approved by NMPA, followed by the quadrivalent vaccine Jiadaxiu and the nine-valent vaccine Jiadaxiu were approved in 2017 and 2018. Whether foreign or domestic, both GlaxoSmithKline and Merck have monopolies on the cervical cancer vaccination market, and the two companies are subject to the number of NPPA approvals, and the market has been in short supply for quadrivalent and nine-valent HPV vaccines.
On April 21, 2020, the bivalent human papillomavirus vaccine (E. coli) (drug name: Xinkoning) jointly developed by Xiamen Wantai and Xiamen University and produced by Xiamen Wantai has been approved by NMPA, which is the first self-developed cervical cancer vaccine in mainland China, the third cervical cancer vaccine in the world and the first approved in China. The vaccine mainly protects against the high-risk virus type 16/18, with the first batch of 93,000 units issued. For the physiological characteristics and genotypes of Asian women, the domestic approved vaccines and international standards have slightly adjusted the applicable age of women. The age of application for nine-valent HPV vaccine is 16-26 years, and the age of application for bivalent and quadrivalent HPV vaccines is 9-45 years and 20-45 years, respectively (Table 1). In the current shortage of vaccines, the vaccine supply situation in various regions is very different, and it is recommended that everyone be vaccinated in an orderly manner according to individual needs and meet the requirements of government epidemic prevention and control.
Table 1 Comparison of HPV vaccines listed in China
Source: NMPA | Tabulation: Bio Exploration Editorial Team
Due to the constraints of NMPA approvals and the insufficient capacity of vaccine manufacturers, the market supply of HPV vaccines is still in short supply. If the HPV vaccination procedure is changed to two or one injection, the market supply will be released exponentially, greatly alleviating the vaccine shortage. However, it will also have a negative impact on the expected revenue of HPV vaccine manufacturers, and its profit space will be greatly compressed.
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Resources:
[1]https://www.who.int/news/item/11-04-2022-one-dose-human-papillomavirus-(hpv)-vaccine-offers-solid-protection-against-cervical-cancer
[2] Basu P, Malvi SG, Joshi S, et al. Vaccine efficacy against persistent humanpapillomavirus (HPV) 16/18 infection at 10 years after one, two, and three doses of quadrivalent HPV vaccine in girls in India: a multicentre, prospective, cohort study. Lancet Oncol. 2021 Nov;22(11):1518-1529. doi:10.1016/S1470-2045(21)00453-8. Epub 2021 Oct 8. Erratum in: Lancet Oncol. 2022 Jan;23(1):e16. PMID: 34634254; PMCID: PMC8560643.
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