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. 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 U.S. and Mexico to evaluate efficacy, safety and immunogenicity." bur-leg/reb