Walvax COVID-19 vaccine

AWcorna, originally termed ARCoV[2] and also known as the Walvax COVID-19 vaccine, is an mRNA COVID-19 vaccine developed by Walvax Biotechnology, Suzhou Abogen Biosciences, and the PLA Academy of Military Science.[3] In contrast to other mRNA COVID-19 vaccines, such as those by Pfizer-BioNTech and Moderna, this vaccine primarily targets the SARS-CoV-2 receptor-binding domain of the spike protein, rather than the entire spike protein.[4] It is approved for Phase III trials in China,[5] Mexico,[6] Indonesia,[7] and Nepal.[8]

ARCoV
Vaccine description
TargetSARS-CoV-2
Vaccine typemRNA
Clinical data
Routes of
administration
Intramuscular
Identifiers
CAS Number
DrugBank

It was granted emergency use approval in Indonesia in September 2022.[9]

Manufacturing

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ARCoV is an mRNA vaccine which consists of lipid nanoparticle–encapsulated mRNA encoding the receptor binding domain of SARS-CoV-2. It was the first mRNA vaccine to be approved for clinical trials in China. Manufactured as a liquid, ARCoV is thermostable at room temperature for at least 1 week.[3] Reuters later reported that it can be stored at (2–8 °C) for six months.[6]

Scrips noted that Abogen created its own solid lipid nanoparticle to deliver the vaccine.[10]

In December, Walvax started constructing a facility to produce 120 million doses of the vaccine each year.[11] If successful, production of ARCoV could start in early 3rd quarter 2021.[12]

Clinical trials

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Phase I and II trials

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Preclinical studies in mice and primates have shown ARCoV elicited a Th1-biased cellular response and robust antibodies against SARS-CoV-2.[3][13]

In June 2020, Walvax began a Phase I trial to evaluate safety, tolerance, and preliminary immunogenicity with 168 participants aged 18–59 in Hangzhou divided into low-dose, medium-dose, and high-dose groups.[14]

In January 2021, Walvax began a Phase II trial to evaluate immunogenicity and safety of different doses with 420 participants aged 18–59 in Yongfu and Xiangfen divided into low-dose, medium-dose, high-dose, and placebo groups.[15]

In January 2022, the outcome of a Phase 1 study conducted in Shulan (Hangzhou, Zhejiang Province, China) was published in The Lancet. The vaccine doses trialed were 5, 10, 15, 20, 25 μg, and placebo. The trial measured anti-SARS-CoV-2 RBD IgG using a standardised ELISA, and neutralising antibodies using pseudovirus-based and live SARS-CoV-2 neutralisation assays. IFN-γ and IL-2 production were also measured, so are side effects. It was determined that fever was the most common systemic adverse reaction, but most of the fever resolved within 2 days after vaccination. The 15 μg group induced the highest titre of neutralising antibodies, which was about twofold more than the antibody titre of convalescent patients with COVID-19. All doses were well tolerated. A surprising unsolicited adverse reaction was a low lymphocyte count in those receiving the vaccine. This occurred in the majority of vaccinated individuals regardless of the dose, whereas only 10% of the placebo group encountered such adverse reaction. The authors pointed out that the lymphocyte count recovered to normal after 4 days.[16]

Low lymphocyte count could be a significant adverse event, especially for individuals who are unknowingly infected with SARS-CoV-2 at the time of vaccination. It is well known that a SARS-CoV-2 infection induces a decreased lymphocyte count,[17] and those with a lower lymphocyte count following infection face a significantly worse prognostic.[18] Considering that those infected by the SARS-CoV-2 are already under the strain of a low lymphocyte count, it will be imperative to ensure that those being vaccinated in the future are not infected by the virus at the time of vaccination.

Phase III trials

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The Phase III trials would enroll an estimated 28,000 participants. Elderly people over 60 years old are planned to comprise 25% of trial participants and randomly assigned into the study group and control group at a ratio of 1:1.[19]

In July 2021, Phase III trials started in Yunnan and Guangxi in China with 2,000 people. Those provinces had previously experienced occasional small outbreaks from imported cases.[5]

In August 2021, Phase III trials were approved in Mexico with 6,000 people.[7] Previously in 2020, Walvax had previously expressed an interest in making the vaccine in Mexico.[20]

In August 2021, Phase III trials were approved in Indonesia.[7]

In July 2021, Phase III trials were awaiting approval by Malaysia's National Pharmaceutical Regulatory Agency (NPRA).[21]

In August 2021, Phase III trials were approved in Nepal with 3,000 people in Dharan.[8]

Colombia, Pakistan, and Turkey are other countries being considered for further trials.[22]

References

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  1. ^ "Patent Landscape Report COVID-19-related vaccines and therapeutics" (PDF).
  2. ^ Liu X, Li Y, Wang Z, Cao S, Huang W, Yuan L, et al. (August 2022). "Safety and superior immunogenicity of heterologous boosting with an RBD-based SARS-CoV-2 mRNA vaccine in Chinese adults". Cell Research. 32 (8): 777–780. doi:10.1038/s41422-022-00681-3. PMC 9197092. PMID 35701541.
  3. ^ a b c "SARS-CoV-2 mRNA vaccine". go.drugbank.com. Retrieved 10 April 2021.
  4. ^ Chen GL, Li XF, Dai XH, Li N, Cheng ML, Huang Z, et al. (March 2022). "Safety and immunogenicity of the SARS-CoV-2 ARCoV mRNA vaccine in Chinese adults: a randomised, double-blind, placebo-controlled, phase 1 trial". The Lancet. Microbe. 3 (3): e193–e202. doi:10.1016/S2666-5247(21)00280-9. PMC 8786321. PMID 35098177.
  5. ^ a b Ma J (22 July 2021). "Domestic clinical trials planned for China's mRNA Covid-19 vaccine". South China Morning Post. Retrieved 23 July 2021.
  6. ^ a b "Mexico to start late-stage clinical trial for China's mRNA COVID-19 vaccine". Reuters. 11 May 2021. Retrieved 14 May 2021.
  7. ^ a b c Pinghui Z (1 September 2021). "Indonesia, Mexico approve phase 3 trials of Chinese mRNA vaccine hopeful". South China Morning Post. Retrieved 1 September 2021.
  8. ^ a b "Nepal approves late-stage trials for Chinese mRNA vaccine candidate". Reuters. 27 August 2021. Retrieved 28 August 2021.
  9. ^ Widianto S, Liu R (30 September 2022). "A Chinese mRNA COVID vaccine is approved for the first time - in Indonesia". Reuters. Retrieved 18 November 2022.
  10. ^ Yang B (14 May 2021). "How A Small Chinese Biotech Is Taking On mRNA Vaccine Giants". Scrip.
  11. ^ Liu R (21 December 2020). "China starts work on plant for mRNA-based COVID-19 vaccine candidate - media". Reuters. Retrieved 10 April 2021.
  12. ^ Pinghui Z (13 April 2021). "China's first mRNA vaccine ready for final stage trials". South China Morning Post. Retrieved 13 April 2021.
  13. ^ Zhang NN, Li XF, Deng YQ, Zhao H, Huang YJ, Yang G, et al. (September 2020). "A Thermostable mRNA Vaccine against COVID-19". Cell. 182 (5): 1271–1283.e16. doi:10.1016/j.cell.2020.07.024. PMC 7377714. PMID 32795413.
  14. ^ "A Phase I clinical trial to evaluate the safety, tolerance and preliminary immunogenicity of different doses of a SARS-CoV-2 mRNA vaccine in population aged 18–59 years and 60 years and above". Chinese Clinical Trial Register. 24 June 2020. ChiCTR2000034112. Archived from the original on 11 October 2020. Retrieved 6 July 2020.
  15. ^ "A Phase II clinical trial to evaluate the immunogenicity and safety of different doses of a novel coronavirus pneumonia (COVID-19) mRNA vaccine in population aged 18-59 years". chictr.org.cn. Chinese Clinical Trial Registry. Archived from the original on 16 March 2021. Retrieved 20 March 2020.
  16. ^ Chen GL, Li XF, Dai XH, Li N, Cheng ML, Huang Z, et al. (March 2022). "Safety and immunogenicity of the SARS-CoV-2 ARCoV mRNA vaccine in Chinese adults: a randomised, double-blind, placebo-controlled, phase 1 trial". The Lancet. Microbe. 3 (3): e193–e202. doi:10.1016/S2666-5247(21)00280-9. PMC 8786321. PMID 35098177.
  17. ^ Deng Z, Zhang M, Zhu T, Zhili N, Liu Z, Xiang R, et al. (September 2020). "Dynamic changes in peripheral blood lymphocyte subsets in adult patients with COVID-19". International Journal of Infectious Diseases. 98: 353–358. doi:10.1016/j.ijid.2020.07.003. PMC 7334931. PMID 32634585.
  18. ^ Zhang HJ, Qi GQ, Gu X, Zhang XY, Fang YF, Jiang H, Zhao YJ (July 2021). "Lymphocyte blood levels that remain low can predict the death of patients with COVID-19". Medicine. 100 (28): e26503. doi:10.1097/MD.0000000000026503. PMC 8284734. PMID 34260527.
  19. ^ Clinical trial number NCT04847102 for "A Global, Multi-center, Randomized, Double-blind, Placebo-controlled, Phase III Clinical Trial to Evaluate the Protective Efficacy, Safety, and Immunogenicity of a SARS-CoV-2 Messenger Ribonucleic Acid (mRNA) Vaccine Candidate in Population Aged 18 Years and Above" at ClinicalTrials.gov
  20. ^ Daniel FJ (12 August 2020). "Mexico to trial China, U.S. COVID-19 vaccines, may produce some". Reuters. Retrieved 10 April 2021.
  21. ^ Daim N, Yunus A (27 July 2021). "Dr Adham: Covid-19 vaccine development in recruitment phase". New Straits Times. Retrieved 28 July 2021.
  22. ^ Pinghui Z (12 May 2021). "Late-stage trial of Chinese mRNA Covid-19 vaccine to begin in Mexico". South China Morning Post. Retrieved 17 May 2021.