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SINOVAC Addresses COVID-19 Mutations with Broad-Spectrum Neutralizing Antibody Products: SA55 Injection and Nasal Spray Approved for Clinical Trial in China


May 29, 2023, Beijing, China – Sinovac Biotech Ltd. ("SINOVAC" or the "Company") (NASDAQ: SVA), a leading provider of biopharmaceutical products in China, announced its Anti-COVID-19 Antibody SA55 for Injection, which is intended for the treatment of COVID-19 infections, was approved on May 24 for clinical trial in China.


This follows the National Medical Products Administration's approval in April for the clinical trial of the use of the SA55 Nasal Spray in the prevention of COVID-19 infections.


To effectively combat the constantly mutating strains of the novel coronavirus, SINOVAC has been developing several broad-spectrum neutralizing antibody products, including Anti-COVID-19 Antibody SA55 for Injection and SA55 Nasal Spray.


The broad-spectrum neutralizing antibody SA55 was founded by a research team led by Dr. Yunlong Cao, researcher at Peking University’s Biomedical Pioneering Innovation Center. Based on high-throughput epitope determination, the team proposed that broad neutralizing antibody therapies should target non-immunodominant epitopes within the receptor-binding domain to circumvent escape mutations driven by herd-immunity. SA55 was discovered within a large repertoire of broad-spectrum sarbecovirus neutralizing antibodies found in individuals who had recovered from SARS and were subsequently vaccinated against SARS-CoV-21. Further studies underscore the efficacy of SA55 in neutralizing the omicron variant and its sublineages, such as XBB, XBB.1, and XBB.1.52.


"SA55 is almost absent in the current population immunity and is currently the only antibody in clinical development that is effective against all known circulating strains of the novel coronavirus," said Dr. Yunlong Cao, during a recent interview with Science and Technology Daily.


The injection can be used to treat and prevent severe cases, which is particularly useful to elderly and immunocompromised individuals, or those ineligible for vaccination or with poor immune responses, he added.


With these latest approvals, SINOVAC will start clinical trials for the injection and nasal spray forms of the neutralizing antibody SA55. By leveraging its extensive experience in COVID-19 vaccine development and production, SINOVAC is capable of large-scale manufacture of these broad-spectrum neutralizing antibody products in compliance with Good Manufacturing Practice standards.


To date, more than 2.9 billion doses of SINOVAC’s COVID-19 vaccine, CoronaVac®, have been shipped globally, making the Company one of the biggest COVID-19 vaccine manufactures in the world.




1.Cao, Yulong, et al. "Rational identification of potent and broad sarbecovirus-neutralizing antibody cocktails from SARS convalescents." Cell reports 41.12 (2022): 111845.


2.Yue, Can et al. “ACE2 binding and antibody evasion in enhanced transmissibility of XBB.1.5.” The Lancet. Infectious diseases vol. 23,3 (2023): 278-280. doi:10.1016/S1473-3099(23)00010-5



Sinovac Biotech Ltd. (SINOVAC) is a China-based biopharmaceutical company that focuses on the R&D, manufacturing, and commercialization of biomedical products that protect against human diseases.

SINOVAC's product portfolio includes vaccines against COVID-19, enterovirus 71 (EV71) infected hand-foot-mouth disease (HFMD), hepatitis A, varicella, influenza, poliomyelitis, pneumococcal disease, mumps, etc.

The COVID-19 vaccine, CoronaVac®, has been approved for use in more than 60 countries and regions worldwide. The hepatitis A vaccine, Healive®, passed WHO prequalification requirements in 2017. The EV71 vaccine, Inlive®, is an innovative vaccine under "Category 1 Preventative Biological Products" and commercialized in China in 2016. In 2022, SINOVAC's Sabin-strain inactivated polio vaccine (sIPV) and varicella vaccine were prequalified by the WHO.

SINOVAC was the first company to be granted approval for its H1N1 influenza vaccine Panflu.1®, which has supplied the Chinese government's vaccination campaign and stockpiling program. The Company is also the only supplier of the H5N1 pandemic influenza vaccine, Panflu®, to the Chinese government stockpiling program.

SINOVAC continually dedicates itself to pipeline development including but not limited to new technology, new vaccines as well as other biomedical products. We will constantly explore global opportunities of strategic expansion.


For more information, please visit the Company’s website at



Sinovac Biotech Ltd. 

PR Team