President Biden stated that the US would have enough coronavirus vaccines for all American adults by the end of May, two months earlier than he had previously said, after regulators authorized the one-shot Johnson & Johnson vaccine and Merck & Co. agreed to help produce it. Mr. Biden also called on states to give priority to teachers, school staff and child-care workers for vaccinations, as virtual learning continues for many students across the country. Several teachers unions have made vaccinations part of their negotiations for returning to in-person teaching. Mr. Biden stated that 30 states are giving priority to such workers for the shot. Mr. Biden stated that the federal pharmacy program would give priority to teachers, and he set a goal for those workers to get at least one dose of the vaccine by the end of March. Mr. Biden said the partnership to make the new J&J vaccine , which was cleared by regulators on Saturday, is “the type of collaboration between companies we saw in World War II. “He stated that the US will have enough supply for all adults by the end of May, but it wasn’t immediately clear when everyone will be able to get the shot.