After Donald Trump’s health secretary shared “important” news about a potential coronavirus vaccine on Tuesday, the country’s top expert on infectious disease stepped in and tamped down expectations.

Speaking with reporters outside the White House, Health and Human Services Secretary Alex Azar said that a potential vaccine for the novel coronavirus had been developed by scientists “within three days,” and that on Monday the Food and Drug Administration authorized the “entry of that vaccine into Phase 1 clinical trials.”

Alex Azar says that scientists have developed a potential vaccine after three days pic.twitter.com/w1xw07ZWSb

— Acyn Torabi (@Acyn) March 3, 2020

After Azar’s optimistic remarks, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, stepped in and made it clear that the US is still at least 12 to 18 months from developing a vaccine for the novel coronavirus.

Fauci said he wanted to “caution everybody” that what Azar described is only the first phase of the development of the vaccine.

“The whole process is going to take a year, a year and a half, at least,” Fauci said while standing a few feet away from Trump.

Fauci has to tamp down on vaccine expectations which causes the President to ask him to talk about therapeutics pic.twitter.com/gUrOVs0l8H

— Acyn Torabi (@Acyn) March 3, 2020

Twitter was absolutely shocked that the HHS Secretary would boldly lie about a vaccine:

This is so unbelievably irresponsible. Shame on Azar!

(If it's not immediately obvious why, see the next tweet in this thread in which Dr. Fauci almost jumps out of his shoes trying to rein in these deceitful politicians. And Azar's a former drug company exec, who knows better.) https://t.co/5tyzhyzZJ8

— Walter Shaub (@waltshaub) March 3, 2020

But it's not true, so the doctors forced him to walk it back. We've gone from fake news to fake vaccines. America, this is not okay. https://t.co/jeDuCyF7VL

— Randi Mayem Singer (@rmayemsinger) March 3, 2020

I am sorry… I do not trust him and everyone in the executive branch under Trump. Trump is a liar and a thief and a criminal. How are we suppose to just accept when he says Americans go sit on your a@@ https://t.co/KapwMwAEtx

— Cotsdi (@cotsdi) March 3, 2020

I just spent a couple hours reading every coronavirus story on the internet and this video made me more anxious than any of them https://t.co/Xd0PV43mUR

— Tom Gara (@tomgara) March 3, 2020

<scratches out "flu" and writes in "Glorious Trump Saves the World Vaccine" on bottle> https://t.co/DzFvLr6LTV

— Stonekettle (@Stonekettle) March 3, 2020