GSK gives Clover adjuvant for vaccine against 'indispensable' COVID-19 protein

GlaxoSmithKline has struck a deal to provide its pandemic adjuvant to Clover Biopharmaceuticals for use in a COVID-19 vaccine candidate. Clover is one of a clutch of organizations working to tackle COVID-19 by targeting a protein the novel coronavirus needs to enter host cells.

China’s Clover, which is based 600 miles west of the focal point of the COVID-19 outbreak, began work on a coronavirus vaccine late last month. Clover entered the race to develop a vaccine on the strength of earlier work to develop recombinant subunit-trimer vaccines for HIV and other enveloped RNA viruses. Animal data from those programs gave Clover confidence its platform for producing covalently-trimerized fusion proteins is applicable to COVID-19.

Now, GSK has lent its support to Clover’s efforts to test that hypothesis. GSK is providing its AS03 adjuvant technology to Clover, which plans to incorporate the mix of squalene, DL-α-tocopherol and polysorbate into its preclinical tests. 

GSK used AS03 in the Pandemrix vaccine it developed to protect people against a pandemic H1N1 strain that circulated in 2009 and 2010. Clover, like GSK before it, is looking to the adjuvant to boost the immune response triggered by its vaccine, thereby enabling it to provide protection using smaller amounts of antigen. Through that immune-boosting effect, adjuvants can make antigen supplies go further and, in doing so, enable more people to receive a vaccine. 

The Coalition for Epidemic Preparedness Innovations (CEPI) has also entered into an agreement with GSK to secure access to AS03. CEPI coordinated an agreement between GSK and the University of Queensland, Australia.

Clover thinks it is equipped to advance a vaccine candidate faster than other organizations. Having raised more than $100 million in recent years, Clover has a mammalian cell culture-based expression system and in-house manufacturing facility. Clover applied the capabilities to COVID-19, leading it to issue a statement about the successful production of a vaccine less than two weeks after it revealed it was working on a candidate.

The vaccine is designed to resemble a spike protein found on the COVID-19 envelope. When the host immune system encounters the vaccine, Clover thinks it will produce neutralizing antibodies that will provide protection in the event of infection with COVID-19.

Other organizations have also taken an interest in the spike protein. Last week, U.S. researchers published the cryo-EM structure of the protein. The researchers said the protein has an “indispensable function,” leading them to foresee a role for the protein in antibody-mediated neutralization and vaccines.