Vaccine specialist Novavax (NVAX -0.95%) announced the launch of a phase 2b clinical trial in South Africa to test the effectiveness of its coronavirus vaccine, NVX-CoV2373. The trial is an opportunity for the company to test the vaccine in an environment where the pandemic is surging during the cold weather of winter. South Africa has had more than half the COVID-19 cases on the African continent.

Vial of coronavirus vaccine.

Image source: Getty Images.

Novavax's vaccine consists of an antigen derived from the coronavirus spike protein plus a proprietary adjuvant, an ingredient that boosts the body's immune response. The company released phase 1 data from a phase 1/2 trial of the vaccine on August 8, which showed that NVX-CoV2373 produced antibodies to the virus numerically superior to levels found in patients who have recovered from the disease. The phase 2 portion of that trial will begin with about 1,500 adults in the U.S. and Australia this month. The phase 2b test announced today will enroll about 2,665 healthy adults and about 240 medically stable, HIV-positive adults.

Novavax is somewhat behind the leaders in the race for an approved vaccine for COVID-19, but the level of transmission in South Africa may give the company a chance to evaluate the efficacy of its vaccine very quickly. The company has also already lined up manufacturing capacity for over 2 billion doses.