Novavax's COVID-19 jab is more than 90 percent effective, including against coronavirus variants, the vaccine maker said Monday after a large-scale US study.

An illustration picture shows vials with Covid-19 Vaccine stickers attached and syringes with the logo of US biotech company Novavax, on November 17, 2020. (File photo: AFP)

The jab "demonstrated 100% protection against moderate and severe disease, 90.4% efficacy overall," the company said in a statement, adding "the study enrolled 29,960 participants across 119 sites in the US and Mexico to evaluate efficacy, safety and immunogenicity."