Vaccine Company Lists in Hong Kong with 4,000 Times Oversubscription

The final issue price for Ab&B Bio-Tech was set at HK$12.90 per share, with a board lot of 200 shares. The global offering involved a total of 33.4426 million shares. The public offering segment received approximately 191,000 applicants and was oversubscribed by approximately 4,006.6 times, with the final amount raised reaching HK$431 million. CITIC Securities and CMB International Securities Limited acted as its joint sponsors.

For this global offering, Ab&B Bio-Tech introduced cornerstone investors Jiaxing Xinyang Private Equity Fund Management Co., Ltd and Huatai International Financial Holdings Company Limited, who subscribed to shares amounting to US$13 million (approximately HK$102 million).

Founded in 2015, Ab&B Bio-Tech is a vaccine company headquartered in Jiangsu, China. As a biotech company that did not meet the profit, revenue, or cash flow requirements under Rules 8.05(1), (2), or (3) of the Listing Rules, Ab&B Bio-Tech listed on the HKEX Main Board under Chapter 18A, which governs the listing of biotech companies.

R&D Portfolio and Core Products of Ab&B Bio-Tech

As of the last practicable date, Ab&B Bio-Tech holds 190 patents in China, including 37 invention patents and 153 utility model patents. Its product pipeline includes two core products and 11 vaccine candidates, covering multiple disease areas with large vaccination demands. Among them, Quadrivalent Subunit Influenza Vaccine (brand name: Hui Er Kang Xin) was approved by China’s National Medical Products Administration (NMPA) in May 2023 for use in individuals aged three and above. It is the first and currently the only approved vaccine of its type in China. Commercialization commenced in September 2023, generating revenues of RMB 52.2 million, RMB 259.6 million, and RMB 0.4 million in 2023, 2024, and the first three months of 2025, respectively. The company is currently developing an extended dosage form of this vaccine for the 6 to 35-month age group, has completed Phase III clinical trials, and submitted a New Drug Application (NDA) to the NMPA in June 2024, with approval expected in the third quarter of 2025.

The other core product, Lyophilized Human Rabies Vaccine (Human Diploid Cell) has completed Phase I clinical trials, demonstrating a good safety profile, and is planned to initiate Phase III clinical trials in the third quarter of 2025. Other pipeline products include a Trivalent Subunit Influenza Vaccine, whose protective coverage aligns with the WHO-recommended virus strains for the 2024-2025 Northern Hemisphere seasonal influenza vaccine, and a 23-valent Pneumococcal Polysaccharide Vaccine (PPSV23), for which the company implemented significant process improvements after completing Phase I trials, adopting ion-exchange column chromatography instead of ethanol precipitation.

Competitive Strengths of Ab&B Bio-Tech

Ab&B Bio-Tech’s strengths are reflected in the potential of its core products in the field of upgraded traditional vaccines, its diversified market demand-driven vaccine pipeline, leading R&D technology platforms, sufficient production capacity, its academically-driven marketing system, and an experienced management team supported by well-known shareholders. In R&D, the company has established three major technology platforms: Genetic Engineering and Protein Expression & Purification Platform, mRNA Vaccine Research Platform, and Adjuvant Development & Production Platform. For the years 2023, 2024, and the first three months of 2025, R&D expenses were RMB 283.2 million, RMB 205.6 million, and RMB 46.5 million, respectively, with R&D investment in the core products—Quadrivalent Subunit Influenza Vaccine and Lyophilized Human Rabies Vaccine—being allocated reasonably according to their development stages.

Production Capacity of Ab&B Bio-Tech

Regarding production capacity, all of Ab&B Bio-Tech’s Quadrivalent Subunit Influenza Vaccine products and vaccines for clinical trials are manufactured at its No. 1 Manufacturing Facility in Taizhou. It currently operates three production lines with designed annual capacities of 4 million doses for influenza vaccine, 5 million doses for rabies vaccine, and 15 million doses for pneumococcal vaccine, respectively. In 2023, 2024, and the first three months of 2025, the production output of the Quadrivalent Subunit Influenza Vaccine was 1.2 million doses, 1.8 million doses, and zero doses, with capacity utilization rates of 30.2%, 45.8%, and zero, respectively. The company is currently conducting process verification for a second influenza vaccine production line, expected to commence operation before the end of 2026, with a designed annual capacity identical to the existing line.

Customer Portfolio of Ab&B Bio-Tech before IPO

Ab&B Bio-Tech’s customers are exclusively district and county-level Centers for Disease Control and Prevention (CDCs) in China. It also faces competition in the market from large domestic and international pharmaceutical companies and biotech firms based on vaccine pipelines, technology platforms, production facilities, and processes. Prior to its IPO, the company completed three rounds of financing, raising a total of RMB 994.38 million. Investors included Nanjing Gaotejia, Yingke Innovation and Sealand Innovation, among other experienced investment institutions focused on the biotechnology and healthcare industries. After the completion of the global offering, these investors will hold approximately 7.55%, 4.37%, and 4.04% of the company’s issued share capital, respectively.

Risk factors faced by Ab&B Bio-Tech before and after IPO

Risk factors faced by the company include the complexity and uncertainty of vaccine R&D, regulatory approval risks, ongoing regulatory obligations, product safety risks, risks related to winning tenders, and risks associated with a single source of revenue. Notably, due to the seasonal nature of influenza vaccines, the company accepts returns of unused vaccines after the end of each flu season. The actual product return rate in 2023 was 32.5%, higher than the initial estimate. The company expects to report a net loss for the 2025 financial year. It is noteworthy that its products are subject to seasonal returns.

Strategic Allocation of IPO Proceeds to Fuel R&D and Growth

The net proceeds from the listing, approximately HK$431 million, will be primarily used for the research, development, and registration of core products and pipeline vaccines: approximately 63.6% will be allocated to core product development and domestic and international registration (32.4% for overseas market registration of the Quadrivalent Subunit Influenza Vaccine and 31.2% for Phase III clinical trials and registration of the Lyophilized Human Rabies Vaccine); approximately 18.1% will be used for the development and registration of other pipeline vaccines; approximately 8.4% will be dedicated to process improvement and commercialization capability enhancement; approximately 4.9% will be allocated for technology platform development; and the remainder will be used for working capital and general corporate purposes. Total listing-related expenses amounted to approximately HK$54.4 million, including total underwriting commissions and fees, HKEX listing fee, transaction levy and HKEX trading fee, legal and other professional fees, printing costs, and all other expenses related to the global offering.

In summary, Ab&B Bio-Tech’s Hong Kong listing not only provides the company with new capital but also helps alleviate current financial pressures and promotes the R&D and commercialization process of its core products. In the short term, Ab&B Bio-Tech will focus on market expansion for its Quadrivalent Subunit Influenza Vaccine and the clinical advancement of its R&D pipeline. In the long term, it is committed to building a diversified vaccine product portfolio, continuously enhancing its R&D and production capacity levels, and further consolidating its competitiveness in both the Chinese and international markets.