President Donald Trump with Director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health Anthony Fauci, center, and Department of Health and Human Services Secretary Alex Azar, speaks to reporters on the South Lawn, on Tuesday, March 3. AP Photo/Manuel Balce Ceneta

Dr. Anthony Fauci, the head of the National Institute of Allergy and Infectious Diseases, said the process to get a potential coronavirus vaccine is expected to take a year to a year and a half.

He made the remarks at the White House following a briefing and tour of the National Institutes of Health in Maryland with President Trump and Health and Human Services Secretary Alex Azar.

Fauci noted that researchers would follow standard testing protocols and that the first trial vaccines would be given to healthy patients — to ensure there would not be any unintended side effects. "I don’t want to over promise, I said a month and a half the other day, it may be a month or so. And then very soon we’ll be sticking the first person with the vaccine. But I want to caution everybody, that’s only the first stage of the development of the vaccine," he said.

Fauci added that researchers must be confident that the vaccine works before distributing it widely and said he conveyed that to the President.

He said a phase one trial could start in about a month, and a phase two trial wouldn’t start for three to four months after that.

The CDC's website says all vaccine trials go through three testing phases before potential approval, including first administering the trial vaccine to small groups of people. The second phase clinical study is then expanded and the trial vaccine is given to people who have characteristics such as age and physical health similar to those for whom the new vaccine is intended.

In phase three, the vaccine is given to thousands of people and tested for efficacy and safety.