Pfizer’s first interim efficacy analysis results of its coronavirus vaccine suggested a 90% success rate, putting the company on pace to apply this month for emergency-use approval from the Food and Drug Administration. The FDA says vaccines must be at least 50% effective.

The company said 50 million doses of its two-shot vaccine could be available globally by the end of 2020 and as many as 1.3 billion in 2021.

“I think we can see light at the end of the tunnel,” Pfizer chairman and chief executive officer Albert Bourla said in an interview. “I believe this is likely the most significant medical advance in the last 100 years, if you count the impact this will have in public health, global economy.”

The analysis looked at 94 confirmed COVID-19 cases in a study that has enrolled nearly 44,000 people in the U.S. and five other countries. It will continue until it records 164 infections among the volunteers.

Dr. Anthony Fauci said the 90% efficacy rate was “just extraordinary” and exceeded expectations. He has said he would be happy with a COVID-19 vaccine that was 60% effective. Flu vaccines are typically about 50% effective.

“It’s going to have a major impact on everything we do with respect to COVID,” Fauci said.

Pfizer did not give further details on the infections but said no serious safety concerns were observed. It cautioned that the initial protection rate might change as the study progresses.

Pfizer’s Bourla said the data was ready and independent monitors met Sunday. “I am very happy,” Bourla said, “But at the same time, sometimes I have tears in my eyes when I realize that this is the end of nine months, day-and-night work of so many people and how many people, billions, invested hopes on this.”