Hundreds more hospitals around the country began dispensing COVID-19 shots to their workers in a rapid expansion of the U.S. vaccination drive Tuesday, while a second vaccine moved to the cusp of government authorization. A day after the rollout of Pfizer-BioNTech’s coronavirus shots, the FDA said its preliminary analysis confirmed the effectiveness and safety of the vaccine developed by Moderna and the National Institutes of Health. A panel of outside experts is expected to recommend the formula on Thursday, with the FDA’s green light coming soon thereafter.