Clover Biopharma vaccine 79% effective against Delta variant

Clover Biopharmaceuticals, a Chinese clinical-stage biopharma company developing vaccines and oncology drugs, announced on Wednesday that its protein-based COVID-19 vaccine candidate was found to be 67 percent effective against COVID-19 of any degree of severity and 79 percent against the highly infectious Delta variant in a large late-stage trial.

Efficacy of the vaccine was 92 percent against the Gamma variant and 59 percent against the Mu variant, the trial showed. Collectively strains of Delta, Gamma and Mu comprised 73 percent of all strains identified in the study.

The vaccine, deploying proteins on the coronavirus to stimulate immunity against COVID-19, is also the first COVID-19 vaccine candidate in the world to demonstrate in a randomized trial significantly reduced risk of COVID-19 disease in previously infected individuals, a growing and increasingly important population as the virus continues to spread worldwide, the company claimed.

The clinical trial enrolled over 30,000 adult and elderly (≥18 years of age) participants at 31 sites in five countries (Philippines, Brazil, Colombia, South Africa, Belgium) across four continents, and is one of the most diverse COVID-19 vaccine clinical trials conducted to date.

"SPECTRA (the name of the project for the trial) enrolled participants during a time when the world encountered the rapid spread of increasingly transmissible SARS-CoV-2 variants and a takeover by Delta," said Joshua Liang, chief executive officer of Clover Biopharmaceuticals.

"Based on our pioneering data, we believe that SCB-2019 (the vaccine candidate) 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," Liang said.

According to an advance purchase agreement with Gavi, or the Vaccine Alliance, the company will provide up to 414 million doses of its protein-based COVID-19 vaccine candidate for procurement through the COVAX facility. COVAX is a global risk-sharing mechanism for pooled procurement and equitable distribution of COVID-19 vaccines that includes more than 190 participating economies.

Clover plans to submit conditional market approval applications to China's National Medical Products Administration, the European Medicines Agency, and World Health Organization in the fourth quarter of the year.

It also plans plan to commence a product launch for the vaccine by the end of 2021.