Reuters The coronavirus has infected nearly 3.9 million people; more than 1.3 million have recovered. A new study found that 99.8% of recovered coronavirus patients developed antibodies. Scientists continue to learn more about what immunity to the virus looks like, but questions remain as to how long it lasts. Visit Business Insider's homepage for more stories. More than 1.3 million people have recovered from the coronavirus, by official counts. People who recover from infectious diseases typically develop immunity for some period of time.