Clover produces subunit vaccine candidate for coronavirus, 2019-nCoV

Credit: Shutterstock.com/ Lemau Studio

Clover Biopharmaceuticals has successfully produced its trimeric Spike-protein (S-Trimer) subunit vaccine candidate for the 2019-nCoV coronavirus via a mammalian cell expression system.

Additionally, scientists from the Chinese biotech had used the newly obtained S-Trimer and successfully detected antigen-specific antibody in sera from multiple fully recovered patients who were previously infected by the virus.

Clover said it is the first company in the world to disclose a 2019-nCoV vaccine candidate that can successfully be recognised by antibodies produced by previously-infected patients, supporting that S-Trimer has preserved the native structure of the viral spike (S) protein and thus may elicit a protective-immune response as a vaccine.

Like other enveloped RNA viruses such as HIV, RSV and Influenza, 2019-nCoV is also an RNA virus that has a trimeric spike (S) protein on its viral envelope.

The trimeric S protein of 2019-nCoV is responsible for binding to host cell surface receptor ACE2 and subsequent viral entry. Symptoms in infected patients include fever, coughing and breathing difficulties, and it can be fatal.

Upon knowing the genomic DNA sequence of this newly identified 2019-nCoV last month, Clover scientists immediately started designing the viral S-protein construct and completed its gene synthesis.

Utilising its patented Trimer-Tag technology, Clover has produced a S-Trimer subunit vaccine that resembles the native trimeric viral spike via a rapid mammalian cell-culture based expression system.

Having one of the largest in-house, commercial-scale cGMP biomanufacturing capabilities in China, Clover could potentially be able to rapidly scale-up and produce large-quantities of a new coronavirus vaccine.

“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,” said Peng Liang, co-founder, Chairman and President of Clover.

“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.

“We remain confident that Clover can be among one of the first companies to develop a successful vaccine to contain the 2019-nCoV epidemic, as well as any future outbreaks of similar coronaviruses”.