Skeptics who claimed in the early days of the COVID-19 pandemic that the virus may have originated not in a wet market but in a laboratory at the Wuhan Institute of Virology were often derided as trafficking in fringe conspiracy theories. But more than a year later, the Wuhan lab theory has gained legitimacy. And as Doug McKelway reports, those who once ridiculed the idea of a laboratory-created virus are themselves coming under greater scrutiny.