Hundreds of millions of people worldwide were adjusting on Wednesday to once-in-a-generation measures to battle the coronavirus crisis that is not only killing the old and vulnerable but also threatening prolonged economic misery. The fast-spreading disease that jumped from animals to humans in China has now infected about 200,000 people and caused nearly 8,500 deaths in 164 nations, triggering emergency lockdowns and injections of cash unseen since World War Two.
