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Clover Biopharmaceuticals has generated a trimeric Spike-protein (S-Trimer) subunit vaccine candidate against the new 2019-nCoV coronavirus.

The company used a mammalian cell expression system to produce the vaccine candidate.

Subsequently, researchers at Clover could identify antigen-specific antibody using S-Trimer in sera of various fully recovered coronavirus-infected patients.

The company is the first to unveil a vaccine candidate that can be detected by antibodies generated by previously-infected patients. This indicates that the vaccine candidate may trigger a protective immune response.

Clover carried out development activities in alliance with China-based Chengdu Hi-Tech Park and Chengdu Clinical Center for Public Health teams.

Clover Biopharmaceuticals co-founder, chairman and president Dr Peng Liang said: “The implication of this discovery is that it not only has validated the correct conformation of our S-Trimer subunit vaccine candidate but also further supports that the new 2019-nCov virus is indeed the culprit for the current epidemic since all previous diagnosis for the viral infections have been based on nucleic acid detection.

“This important finding forms a solid foundation for the continued rapid development of S-Trimer vaccine through pilot production, preclinical efficacy and safety studies, followed by human clinical trials and subsequent large-scale production.”

2019-nCoV is an RNA virus that consists of a trimeric spike (S) protein on its viral envelope. The trimeric S protein enables attachment to host cell surface receptor ACE2 and viral entry.

The company began designing viral S-protein construct last month, completing gene synthesis, following the publication of 2019-nCoV genomic DNA sequence.

Clover Trimer-Tag technology produced an S-Trimer subunit vaccine through a rapid mammalian cell-culture based expression system.

The company’s commercial-scale biomanufacturing capabilities in China should facilitate the production of high quantities of a new coronavirus vaccine.