A top U.S. infectious disease expert applauded the news that a COVID-19 vaccine being developed by U.S. pharmaceutical company Pfizer and German firm BioNTech showed an over 90 percent efficacy rate in early results from its late-stage clinical trial.

At a virtual press conference hosted by The HIV Prevention Trial Network(HPTN) on Monday, Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, said the results are "extraordinary."

Fauci has previously said he would like to see an efficacy rate of 70 to 75 percent in a COVID-19 vaccine, meaning it would protect about three-quarters of people who get vaccinated from becoming infected.

Fauci said the results may indicate that Moderna's vaccine candidate may also have positive results, since both vaccines use similar technology, adding there is hope for two vaccines.

The U.S. Food and Drug Administration(FDA) has set a minimum of 50 percent effectiveness for a vaccine to receive emergency use approval.

Pfizer hopes to have the safety data required for the FDA authorization by mid-November and manufacture up to 50 million doses this year globally and one-point-three billion in 2021.