Yiwu He, the chief innovation officer at the University of Hong Kong, told me that the C.N.B.G. vaccine has already been given to a number of Chinese government officials, under an emergency-use approval granted by the authorities. “I know a few government officials personally, and they told me that they took the vaccine,” he said, in a phone conversation. He thought that the total number was probably around a hundred. “It’s middle-level officials,” he said. “Vice-ministers, mayors, vice-mayors.”