WASHINGTON (AP) — A second COVID-19 vaccine is moving closer to joining the U.S. fight against the pandemic. A panel of independent experts is meeting Thursday to discuss the vaccine made by Moderna. The panel’s review for the Food and Drug Administration is the next-to-last step before the agency decides whether the shots can be used on an emergency basis. The FDA staff issued a positive review earlier in the week, confirming the vaccine’s safety and effectiveness. If the panel gives a thumbs-up, the FDA is expected to give the green light within hours or days. A Pfizer vaccine got the go-ahead last week.