A quarter of doctors who participated in a February survey in the US said they plan to leave their primary care jobs within the next three years because of stress over Covid-19, according to researchers. The survey, conducted by The Larry A. Green Center, a Virginia-based medical research organization, showed that primary care physicians’ stress levels improved as vaccines became widely available in the US last summer, but declined again to pre-vaccine levels when the delta variant of the coronavirus sparked waves of new outbreaks across the country. As of February, only a fifth of the medical…