GEOFF BENNETT: Dr. Anthony Fauci is arguably the world's most famous doctor, and, of course, best known for guiding the country through the COVID-19 pandemic.

But he has also faced right-wing criticism for his assessments and recommendations throughout that period, including some difficult clashes with former President Donald Trump.

Now, after a nearly-six-decade journey, he reflects on his expansive career in a memoir, "On Call: A Doctor's Journey in Public Service."

I sat down with Dr. Fauci last week.

Here's the first part of our interview.

Dr. Anthony Fauci, welcome back to the "NewsHour."

DR. ANTHONY FAUCI, Former Chief Medical Adviser to President Biden: Thank you so much, Geoff.

Good to be here.

GEOFF BENNETT: Well, let's start our conversation where you start the book, your Brooklyn upbringing.

Your parents were first-generation Italian-Americans.

Your dad was a pharmacist who actually bought a drugstore.

And it struck me.

You wrote in the book that over the years, his pharmacy became a combination doctor's office, pharmacy and psychiatrist's couch.

He cared for people.

He cared about people.

How much did that influence your career choice?

DR. ANTHONY FAUCI: I think that was foundational in my career choice, because, ever since I was a child, literally, 8, 9 years old, in pharm -- in the drugstore, delivering prescriptions with my father, the thing that came through with him is that, at that time, as I mentioned in the book, it was kind of a core part of the neighborhood, where people would come for marriage counseling.

Children that are in trouble, they - - do they want to go to the doctor?

Should they go to a physician or not?

And he really cared for the people in the neighborhood.

And I had that kind of DNA of caring for people.

And then that was compounded when I went in my further education of caring for people.

I think that had a major impact in my wanting to go into medicine.

GEOFF BENNETT: And much of the memoir focuses on your role in the early 1980s leading the response to the HIV/AIDS epidemic.

And I didn't realize, until you wrote about it so extensively here, about the ways in which you were heavily criticized, in large part because activists at the time held you responsible for what they saw as the government's slow response to that crisis.

How searing of an experience was that for you?

And what did you learn from it?

What did you take away from it?

DR. ANTHONY FAUCI: Well, it was an enlightening experience because the activists were right.

The rigidity of the scientific approach, the clinical trials process of inclusion and exclusion criteria in the clinical trial, the understandable rigidity of the regulatory process taking so long to get an intervention approved, it worked really well for decades and decades for diseases that were not the way HIV/AIDS was, which was a group of predominantly young gay men who had a disease or were at risk for a disease that was killing all of their friends in a period of 10 months to 12 months from the time they developed symptoms.

They wanted a seat at the table.

They wanted to say, we want some input into the design of the trials, so that we could have greater access.

And we don't want to wait seven years for a drug to get approved.

Understandably, but unacceptably, the scientific community and the regulatory community just said, we know best for you.

We're the scientists.

We're the ones with the experience.

And they kept saying, no, no, no.

We really want a seat at the table.

When we didn't listen, then they started becoming theatrical, iconoclastic, disruptive and confrontative.

As John Lewis used to say, there's trouble and there's good trouble.

They were making good trouble in the field of health in wanting to have a seat at the table.

One of the best things I think I have done in my career was to put aside the theatrics and listen to what they were saying, because what they were saying made absolutely perfect sense.

And I remember saying to myself that, if I were in their shoes, I'd be doing exactly what they were doing.

GEOFF BENNETT: When you describe that experience as enlightening, how did it inform your approach moving forward to confront other epidemics?

DR. ANTHONY FAUCI: Yes.

Yes, listen to the patients.

Listen.

And don't think that everything comes from the top down.

Listen to the community.

Listen to what they're experiencing.

And you're going to make a much better and more appropriate response to whatever the disease challenge is.

That was a lesson that was very well-learned from the activists.

GEOFF BENNETT: Well, over your career, you confronted a long procession of epidemics, HIV, SARS, avian flu, swine flu, Zika, Ebola.

Drawing on the wealth of experience and some post-pandemic hindsight, do you have any sort of fresh insights into why the U.S. was so unprepared for COVID-19?

DR. ANTHONY FAUCI: Yes, I -- there's preparedness and response at a scientific level and at a public health level, as I describe in the book.

From a scientific preparedness and response, we get an A-plus, because the work that we did in investing in basic and clinical research for decades before COVID and the work that we did in all of the things that were medical and scientific allowed us to do something that was completely unprecedented, in collaboration with the pharmaceutical companies, to develop a vaccine from the time the pathogen was identified to the time you were having a safe and effective vaccine going into the arms of people, which was lifesaving, was less than a year.

Completely unprecedented.

That was good.

What was not so good was the public health preparedness, where we had let our local public health system and the interaction between the local public health and the CDC and the federal response, it wasn't always connected as well as it should have been.

And, also, I think it's important to say, because it's the truth, that if ever there was a time when you didn't want to have a public health crisis was at a time of profound divisiveness within our country, where you were having people making decisions about health based on political ideology.

That is the worst possible circumstance.

GEOFF BENNETT: Is there a way to insulate public health messaging and a public health response from partisanship and partisan politics?

DR. ANTHONY FAUCI: Gee, I would hope that there would be.

It would have been really nice if we had a uniform message: Masks work.

Use them.

Vaccines are good and save lives.

Let's do it.

But there was a lot of, as I said, ideological stuff that got mixed up in there that I think confused the issue.

GEOFF BENNETT: Most of the country knows you based on their experience with the pandemic and seeing you at those hourslong White House press briefings, where in some cases you had to correct the information that was being put out by the White House and by the president himself.

How did you navigate that?

DR. ANTHONY FAUCI: It was not comfortable.

I had to make a decision when I saw things being said that were clearly untrue, like it's going to go away like magic, or this drug hydroxychloroquine or what have you worked.

So I just examined within myself and I said, I have a responsibility to preserve my own personal integrity.

And I have a responsibility to the American public.

I felt that very strongly as a physician and a scientist and a public health person.

I have a responsibility to give them the correct information.

It was very tough, because I have a great deal of respect for the presidency of the United States, the office of the presidency.

And I had no antipathy at all towards President Trump.

But when he was saying those things, I had to, when asked, say, no, it's not going to disappear like magic.

No, hydroxychloroquine not only doesn't work, but, in fact, it could harm you.

And that obviously set up a lot of blowback to me from the White House and the White House staff.

GEOFF BENNETT: And you write about that in the book, the ways in which you were undermined and attacked by top aides to then-President Trump, to include Peter Navarro, who is now in prison on a contempt of Congress charge.

What effect did that have on your ability to effectively communicate public health messaging during a pandemic?

DR. ANTHONY FAUCI: Well, it interfered with, because, there were times when I did want to, since I feel I can communicate well with the public, to get out there and continue to tell them what they knew to keep safe, what they must do to keep safe, as things were going on in the epidemic.

And there was a time when, all of a sudden, I got cut off.

You can't just go on PBS or go on any of the major networks or cable without permission from the people in the communications department.

And then there reached the time when they got upset with me because what I was saying was contradictory to the message that the White House wanted to get out, that I got cut off.

And that made it very difficult for me through the easy way to get to the public, through the media.

I mean, they didn't cut me off completely.

I could talk to the press, the print press, and I could talk to the lesser of the communications.

But the big players, they just wouldn't let me on anymore.

GEOFF BENNETT: Tomorrow night, part two of our interview with Dr. Anthony Fauci.

We talk more about his working relationship with Donald Trump, the threats he's faced, and how he views his legacy.