Washington: Scientific studies with poor methodology and inaccurate findings are exacerbating a Covid-19 misinformation crisis that is discouraging vaccination and putting lives at risk.The intense public interest in the pandemic and divisive debate in the United States over how to address it facilitates the spread of faulty research papers online, including by vaccine opponents. And even if a study is retracted, it is too late."Once the paper is published, the damage is irrevocable," said...