Can Clover’s Vaccine Candidate Stand Its Ground Against COVID Variants?

Chinese biotech company Clover Biopharmaceuticals might be holding another piece of the COVID-19 immunity puzzle. On Wednesday, the company said that its adjuvanted protein-based COVID-19 vaccine candidate, dubbed SCB-2019 (CpG 1018/Alum), hit the primary and secondary efficacy endpoints in a Phase II/III clinical trial.

In the global SPECTRA trial, the vaccine candidate showed 100% efficacy against severe COVID-19 and hospitalization, with 84% efficacy against moderate-to-severe COVID-19 in a range of variants. Perhaps most interesting to point out is how it stood its ground against highly transmissible variants. It demonstrated 79% efficacy against the Delta variant, which is currently responsible for 90% of all cases worldwide. It also showed 92% efficacy against the Gamma variant and 59% against the Mu variant.

The SPECTRA trial is one of the most diverse COVID-19 vaccine clinical trials to date, having had over 30,000 adult and elderly participants across four different continents. It is a 1:1 randomized, double-blinded placebo-controlled trial.

“We are pleased that SCB-2019 (CpG 1018/Alum) has successfully demonstrated efficacy against the globally dominant Delta strain and other concerning variants," said Joshua Liang, chief executive officer of Clover Biopharmaceuticals. "Based on our pioneering data, we believe that SCB-2019 (CpG 1018/Alum) could be utilized as an important tool to combat this pandemic, and we remain dedicated to expediting the availability and equitable access of our COVID-19 vaccine candidate for global distribution."

The trial was funded by the Coalition for Epidemic Preparedness Innovations (CEPI), which is a partnership between public, private philanthropic and civil organizations to develop vaccines against future epidemics. Throughout the ongoing pandemic, CEPI has initiated multiple programs to develop vaccines against SARS-CoV-2 and its variants.

"This very encouraging data demonstrates the favorable safety profile of Clover's vaccine and its efficacy against multiple variants of SARS-CoV-2 – including the predominant Delta variant – so it will be a crucial addition to our weaponry in the fight against COVID-19,” said Dr. Richard Hatchett, CEO of CEPI. “CEPI's significant early investments have accelerated the clinical development and manufacturing of the vaccine and will enable equitable access to hundreds of millions of doses through COVAX. As a result of CEPI's partnership with Clover, this vaccine is poised to play a significant role in protecting those most at risk from COVID-19, wherever they are in the world."

Clover plans to use the trial data to submit conditional approval applications to global regulatory authorities, including China NMPA, EMA and WHO, in the fourth quarter with the goal of launching the vaccine by the end of the year.