Coronavirus vaccine trials have their first results — but their promise is still unclear

Still, the early data offer clues as to how coronavirus vaccines might generate a strong immune response. Scientists say that animal data will be crucial for understanding how coronavirus vaccines work, so that the most promising candidates can be quickly identified and later improved. “We might have vaccines in the clinic that are useful in people within 12 or 18 months,” says Dave O’Connor, a virologist at the University of Wisconsin-Madison. “But we’re going to need to improve on them to develop second- and third-generation vaccines.”