President Joe Biden said Tuesday the U.S. expects to take delivery of enough coronavirus vaccine for all adults by the end of May — two months earlier than anticipated — and he pushed states to get at least one shot into the arms of teachers by the end of March to hasten school reopenings. Biden also announced that drugmaker Merck will help produce rival Johnson & Johnson’s newly approved one-shot vaccine, likening the partnership between the two drug companies to the spirit of national cooperation during World War II. “We’re now on track to have enough vaccine supply for every adult in America by the end of May,” Biden said. Despite the stepped-up pace of vaccine production, the work of inoculating Americans could extend well into the summer, officials said, depending both on the government’s capacity to deliver doses and Americans’ willingness to roll up their […]