On Monday, Pfizer, a pharmaceutical company, reported that its coronavirus vaccine was 94 percent effective and still in the process of being modified.

Health professionals said the U.S. vaccine trials and results were “promising but preliminary” since the outcomes were based off on only a 94-participant trial.

Pfizer and BioNTech are expected to put in requests to the U.S. Food and Drug Administration after they collect more data and ask to utilize the vaccines in emergency cases.

“I can’t imagine better news on the vaccine front,” Walid Gellad, the head of the Center for Pharmaceutical Policy and Prescribing at the University of Pittsburgh, told Politico. “Not only is it highly effective based on the press release, but there were 90 cases so we don’t have to deal with the skeptics about interim analyses, and there appeared to be no safety signals.”

Despite promising results from the late trials, Pfizer’s research results still need to undergo peer-review in order for it to be officially published.