Southwest Airlines Co. said Monday that it will require most workers to be vaccinated against Covid-19, the latest carrier to take such a step.

Less than two weeks ago, Southwest’s incoming chief executive officer, Bob Jordan, told Bloomberg News the company was not considering a mandate. Competitor United Airlines Holdings Inc. had announced a vaccine requirement for workers in August and has said recently that 98.5% of employees have complied.

Southwest said its policy goes into effect Dec. 8. Workers can seek exemptions for religious, medical or disability reasons.