WestVac BioPharma Co., Ltd. (WestVac BioPharma) currently possesses mature insect cell expression platform, novel adjuvant platform, bacterial vaccine platform, mRNA vaccine platform, tumor vaccine and immunotherapy platform, with over 20 product pipelines including series of COVID-19 vaccines, multi-valent influenza vaccines, respiratory syncytial virus vaccines, herpes virus vaccines, tumor immunotherapies, and more.
After the outbreak of the COVID-19 pandemic in early 2020, under the strong support of various levels of government, West China Hospital of Sichuan University and WestVac BioPharma actively engaged in the scientific action against COVID-19. Through diligent efforts, many breakthroughs have been achieved. West China Medical Center affiliated to Sichuan University, is the largest national medical center in western China. Its national key laboratory of biologic therapy is the only national key laboratory in China with the theme of "biotechnological treatment of major human diseases", boasting over 150 research and development personnel from multiple disciplines, including 13 Changjiang Scholars/Young Changjiang Scholars and 18 recipients of the National Science Fund for Distinguished Young Scholars. More than 30 high-level papers have been published in journals such as Nature, Science, Nat. Commun., and STTT about COVID-19 vaccines and vaccine-related technologies,. Particularly, the first COVID-19 vaccine article was published in Nature journal (Nature, 2020, 586: 572-577), and more than 50 Chinese and foreign patents have been applied for.
The recombinant COVID-19 vaccine developed by WestVac BioPharma has been approved and funded five times by the Research and Development Specialty Class of the Joint Prevention and Control Mechanism of the State Council. From the primary vaccine of the prototype strain to vaccines targeting variant strains, multicomponent and multi-valent vaccines, and the COVID-19 vaccine targeting the XBB variant strain, the technology has been continuously updated around the ongoing mutations of the COVID-19 viruswith timely development of vaccines targeting the currently prevalent strains.
On July 29, 2020, the research team of WestVac BioPharma published the first research paper on COVID-19 vaccines in the Nature journal. Westvac used an innovative recombinant protein technology route to develop the first insect cell-expressed recombinant COVID-19 vaccine in China (Sf9 cells) - Coviccine®. It also introduced the genes of SARS-CoV-2 into insect cells to prepare the S protein of SARS-CoV-2, inducing the human body to produce antibodies to block virus infection, and achieving large-scale production. Phase I/II clinical trials of Coviccine® were completed in June 2021, and global multicenter Phase III clinical trials involving nearly 40,000 subjectswere conducted in multiple countries. Clinical trials,which were carried out for market access , led to the first Chinese COVID-19 vaccine that entered clinical trials in Japan .
In December 2022, the recombinant COVID-19 vaccine (Sf9 cells) - Coviccine® was approved for emergency use by relevant national authorities. In February 2023, WestVac BioPharma obtained the "Accreditation of Overseas Manufacturers of Pharmaceuticals - Certification for Biologics" in Japan, indicating that the company has reached international advanced level in this field. Trial results of Coviccine® showed that the vaccine has good safety and immunogenicity. WestVac BioPharma continues to follow the trend of the COVID-19 virus mutations and has developed recombinant variant COVID-19 vaccines (Sf9 cells) targeting the Omicron variant and other variants.
At the beginning of 2023, in response to the prevailing variants such as XBB, WestVac BioPharma/West China Hospital of Sichuan University quickly organized research and development efforts to innovate and successfully developed the Recombinant COVID-19 Trivalent (XBB.1.5+BA.5+Delta) Protein Vaccine (Sf9 Cell) and the Recombinant COVID-19 (XBB.1.5) Trimer Protein Vaccine (Sf9 Cell). In June 2023, the Coviccine® trivalent XBB.1.5 vaccine was approved for emergency use by the Chinese national authorities. This marked the world's first approval of an emergency-use vaccine targeting the XBB.1.5 and other variants of the novel coronavirus. Free vaccinations have been conducted at over 10,000 community vaccination sites in more than 300 cities of China nationwide. In December 2023, the Recombinant COVID-19 (XBB.1.5) Trimeric Protein Vaccine (Sf9 Cell) was also approved for emergency use by the Chinese national authorities. In January 2024, the Recombinant COVID-19 Trivalent (XBB.1.5+BA.5+Delta) Protein Vaccine (Sf9 Cell) and the Recombinant COVID-19 (XBB.1.5) Trimeric Protein Vaccine (Sf9 Cell) were successfully selected as the "Top 10 Advances of Chinese Medical Biotechnology of the Year " in 2023 by the China Medicinal Biotechnology Association and the journal "Chinese Medicinal Biotechnology".
WestVac Biopharma leverages the rapid response of the insect cell expression platform on constructing the vector for vaccine to produce the Recombinant Trivalent XBB.1.5 Protein Vaccine of high purity and high quality. The subunit vaccine antigen of Coviccine® Trivalent XBB.1.5 Vaccine is carefully designed based on the structural preciseness of the targeting S-RBD and HR proteins of the COVID-19 XBB.1.5 and other subvariants, and self-assembled into stable trimeric protein particles with squalene-based oil-in-water emulsion adjuvant added after purification and mixing. This novel adjuvant significantly raises the titer of neutralizing antibodies, which enables the trimeric protein vaccine to induce a stronger T-cell immune response. Clinical trial data showed that 14 days after receiving the trivalent XBB.1.5 vaccine, high levels of neutralizing antibodies against the SARS-CoV-2 Omicron variants, including JN.1, BA.2.86, EG.5, HV.1, XBB.1, and XBB.1.5, were induced, with geometric mean titers (GMT) ranging from 900 to 3500, representing a 6.9 to 39-fold increase compared to pre-vaccination levels, demonstrating broad-spectrum efficacy. The GMT against JN.1, BA.2.86, and EG.5 variants were increased by 8.28, 10.48, and 14.90 fold respectively. The protective efficacy of this product against symptomatic COVID-19 caused by SARS-CoV-2 was 93.28% (95%CI: 92.76%, 93.81%) at 14 days and 86.18% (95%CI: 84.24%, 88.12%) at 6 months post-vaccination, while maintaining proven safety. These findings indicated that the Coviccine® trivalent XBB.1.5 vaccine represents a new generation of broad-spectrum COVID-19 vaccines targeting various variants, including XBB, prevalent China domestically and internationally, and fully reflects the advantages and characteristics of the recombinant protein vaccine technology using insect cell expression.
A new study published by Professor Wang Pengfei and related team at Fudan University in BioRxiv indicates that the Coviccine® trivalent XBB.1.5 vaccine induces a stronger neutralizing antibody response against multiple new SARS-CoV-2 variants such as JN.1, BA.2.86, and BA.2.87.1 (originating in South Africa and recently listed by the World Health Organization (WHO) as virus under monitoring(VUM）) compared to XBB strain infected individuals, which were 16.7, 11.9 and 6.0 times higher than those before vaccination respectively, effectively combating a wide range of SARS-CoV-2 variants.
It is suggested that the Coviccine® trivalent XBB.1.5 vaccine is a new generation of broad-spectrum COVID-19 vaccine against XBB variants prevalent in China and abroad. It fully embodies the advantages and characteristics of the recombinant protein vaccine technology route expressed in insect cells.
Moreover, to enhance vaccine safety and accessibility, WestVac BioPharma is developing a nasal spray recombinant variant-specific COVID-19 vaccine (Sf9 cells) targeting mutated strains of SARS-CoV-2. By inducing mucosal immunity,high levels of neutralizing antibodies are produced to improve protective efficiency.. The company is also concurrently developing novel oral anti-COVID-19 drugsand mRNA COVID vaccines, with current trial results indicating that both have proven safety and efficacy in vivo.
