The WHO’s recommendation on HPV vaccines caused the stock prices of three domestic companies to plunge.
In the early morning of April 14th, the domestic agent of Merck HPV vaccine, Zhifei Bio (300122), plunged more than 18% in intraday trading. Wantai Bio (603392), which owns the first domestic bivalent HPV vaccine, fell by the limit to 256.04 yuan per share. The share price of Watson Bio (300142), which has just been approved for the bivalent cervical cancer vaccine, fell by more than 7% in the morning. 
Screenshot of WHO press release
The source of the market crash came from a news from the World Health Organization.
On April 11, local time, the World Health Organization (“WHO”) website released information that from April 4 to April 7, the World Health Organization (WHO) The Strategic Advisory Group of Experts on Immunization (SAGE) convened a meeting and noted that a single dose of the HPV vaccine provides reliable protection, comparable to a 2- or 3-dose regimen.
Regarding the impact of the reduction in the number of HPV vaccination doses, at noon on April 14, Wantai Biological announced that the company was currently approved in China for two The HPV vaccine is available in 3 doses (2 doses for women aged 9-14). Under the current national drug administration policy, such as changes in vaccination doses, a series of clinical, data support and registration change procedures need to be performed, which will take a certain amount of time and will not have a significant impact on the company’s operating performance in the short term.
On the afternoon of April 14th, the news reporter contacted Zhifei Bio, and the phone number of the Office of the Secretary of the Board of Directors was always on the phone. Zhifei Biological’s administrative office staff said on the phone that the company is currently actively following up on the matter. Watson Bio responded to the news reporter and said: “This does not meet the announcement (requirement).”
After the market opened on the afternoon of April 14, the share price of related companies fell. narrow. As of the close, Zhifei Biological fell 14.19% to 116 yuan/share, with a market value of 185.6 billion yuan; Watson Bio fell 3.08% to 49.11 yuan/market value of 78.65 billion yuan; Wantai Bio fell 9.46% to 257.59 yuan/share , with a market value of 156.37 billion yuan.
or affected by three HPV vaccine companiesFalling, on April 14, many stocks in the A-share biological vaccine sector fell. For example, CanSino closed down 3.99%, and Kangtai Bio closed down 1.2%.
What exactly does the WHO say about the HPV vaccine?
It can be seen from the minutes of the meeting published on the official website of the World Health Organization that the meeting discussed various contents such as the new crown vaccine and polio vaccine. Part of it is related to the HPV vaccine.
It is important to note that SAGE noted in the minutes of the meeting that it reviewed new evidence on the efficacy of a single dose of HPV and recommended that women aged 9-14 receive either 1 or 2 doses Doses, single doses provide comparable and high levels of protection, are more effective from a public health perspective (fewer doses required per cancer prevention), require fewer resources and are easier to implement. Likewise, 1 or 2 doses are also suitable for women between the ages of 15 and 20.
The current HPV vaccine policy is 2 doses for girls aged 9-14, 3 or more doses for girls aged 15, and Immunocompromised people, including people with HIV, receive 3 doses. 
Part of meeting minutes on HPV vaccine
Taking into account HPV vaccine coverage, the goal of eliminating cervical cancer by 2030, and the impact of the current COVID-19 pandemic on vaccination, SAGE said it reviewed the Emerging evidence on the efficacy of dose HPV vaccination programs recommends the following immunization schedule: 1 or 2 doses for women aged 9-14 (highest priority group); 1 or 2 doses for women aged 15-20;21 2 doses (6 months apart) for females over 10 years old.
It is worth noting that SAGE emphasizes that more evidence is needed on whether reduced doses provide protection in immunocompromised groups.
The minutes also mentioned that WHO will conduct stakeholder consultations on these important policy changes before revising the position paper on HPV vaccination.
How will changes in HPV vaccine doses affect the industry?
It is not the first time that a single dose of HPV vaccine can actually prevent cervical cancer.
In October 2021, the results of a study led by Partha Basu from the International Agency for Research on Cancer, published in the Lancet Oncology, showed that within 10 years after vaccination The protective effect of a single dose of quadrivalent HPV vaccine against persistent infection of high-risk HPV16 and HPV18 is equivalent to that of two or three doses of quadrivalent vaccine, which can reach more than 90%. About 70% of cervical cancers are caused by viral infections of two subtypes, HPV16 and HPV18. 
The Lancet-Oncology paper on the effect of different doses of HPV vaccine homepage
For the recommendations of this WHO meeting on HPV vaccine, CITIC According to the analysis of the medical team, this meeting only provided a suggestion and did not implement it. From the current vaccination procedure, 2-3 doses are still the main (legal procedure). In addition, WHO’s recommendations are mainly based on concerns about the slow introduction of HPV vaccine into immunization programmes and low overall population coverage, especially in poorer countries, and the core is to address the huge gap between HPV vaccine supply and demand.
Five HPV vaccines have been approved in China. Except for the two domestic vaccines from Wantai Bio and Watson Bio, the other three are imported, namely GlaxoSciences Gram’s bivalent HPV vaccine, Merck’s quadrivalent HPV and nine-valent HPV vaccines, two of which are represented by Zhifei Biological.
The CITIC Pharma team pointed out that even if the vaccination procedure is changed from three injections to two injections in the future, the improvement of industry penetration rate and accessibility is believed to effectively fill the market, which is expected to bring Due to the strong demand for HPV vaccination in related countries in the third world, the export of domestic HPV vaccines is expected to accelerate. At the same time, for Merck’s nine-valent HPV vaccine, it is still in a stage of insufficient production capacity. Whether it is a two-shot or three-shot vaccination program, it is still in a stage of short supply. Don’t worry too much about the impact on the performance of HPV-related companies. .