The ability to distribute vaccines and the fear that the rush to make a vaccine may make it unsafe are significant concerns, according to Dr Francis Collins, director of the National Institutes of Health.
But, he said it's important to look at the positive side.
"This has been an amazing trajectory that we've been on," Collins said, talking on NBC's Meet the Press, reports the CNN.
Within a day or two of getting the virus genome sequence, he said that a vaccine was already starting to be designed. After 62 days, this was being injected into the first phase one trial participants.
"That data which was just published looks extremely good," Collins said.
"So we're on a good path here."
Collins also encouraged people to sign up for vaccine clinical trials, especially is places where the virus is spreading and people who are at higher risk.
Speaking about reports that Russian cyber actors are targeting organizations involved in coronavirus vaccine development, Collins said it wasn't entirely clear to him what it was all about, but that "most of what we do in science, we publish it, we put it out there, people don't have to go hacking to find it. We're all about transparency."
He also said he wasn't sure that there was serious risk involved, "mischief, yes, but serious risk, I'm not so sure."