ohnson & Johnson said Friday that its one-dose coronavirus vaccine was 72% effective in protecting against Covid-19 in the United States. The vaccine, however, was less potent in other regions, it said. The highly anticipated results were based on 468 confirmed Covid-19 infections among the phase three trial’s more than 43,000 volunteers, according to J&J. The company said the trial includes those infected with B.1.351, the new, highly contagious strain found in South Africa. The level of protection varied by region, J&J said, with the vaccine demonstrating 66% effectiveness overall, 72% in the United States, 66% ... (full story)