Moderna said it will ask U.S. and European health regulators on Monday to authorize use of the company’s Covid-19 vaccine, after it was shown to be 94.1% effective in a full analysis of a pivotal study.⠀ ⠀ The timing keeps the vaccine on track to become possibly the second to go into use in the U.S. by year’s end—after one already under regulatory review from Pfizer and BioNTech—with inoculation available to the general public likely in spring or summer.⠀ ⠀ In the 30,000-person trial, 196 subjects developed Covid-19 with symptoms after receiving either the vaccine or a placebo, Moderna said. Of those, 185 had taken a placebo, while only 11 had gotten the vaccine, indicating it protects against the disease. Moderna also said the vaccine appeared to be generally safe, though some subjects developed headaches and other mild to moderate reactions.⠀ ⠀ If the U.S. Food and Drug Administration clears the shot, distribution could start within weeks. Moderna expects a panel of outside experts a...