Fauci was asked during an interview with Fox News host Laura Ingraham if COVID-19 could “disappear” like SARS did in 2004.

“Anything could, Laura, but I must say that the degree of efficiency of transmissibility of this is really unprecedented in anything that I’ve seen. It’s an extraordinarily efficient virus in transmitting from one person to another,” Fauci said. “These kinds of viruses don’t just disappear.”

Earlier in the interview, Ingraham asked why the U.S. is “pegging on going back to normal with a vaccine,” when that wasn’t the case for SARS or HIV/AIDS.

Fauci said it’s inefficient to compare the current pandemic to HIV/AIDS or SARS because the diseases behave differently, calling the rate of transmission in COVID-19 “unprecedented.”

“This is different,” Fauci said. “…So I think it’s a little misleading maybe to compare what we’re going through now with HIV or SARS, they’re really different.”