WASHINGTON, United States (AFP) — US biotech company Moderna announced Covid vaccine is 90 percent effective against all forms of the disease and 95 percent effective against severe disease. The new results come from its ongoing Phase 3 clinical trial involving more 30,000 people across the United States, and the headline efficacy figure is a slight decrease from an earlier figure of 94.1 percent published in the New England Journal of Medicine in December. […]