A study published in the New England Journal of Medicine on Wednesday found that the Novavax coronavirus vaccine is 51 percent effective against the South African COVID-19 variant.

The study of the American-made vaccine was conducted in South Africa and included around 2,700 volunteers who had not previously had the coronavirus, Reuters reports.

Among this demographic, the vaccine was 43 percent effective against the B.1.351 South African strain.

In January, Novavax shared that its vaccine had been shown to be 89.3 percent effective at preventing the coronavirus.