When Anthony Fauci took over as head of the NIAID, his wife gave him a plant for the new office. The office of one of the most celebrated and controversial scientists in U.S. history is still occupied by the palm and the doctor. Not for a long time. The chief medical adviser to President Joe Biden will be stepping down at the end of the year, according to Fauci.

I don't know what to do with this plant. It's a big deal. He joked this week from his NIAID office to Science Senior Correspondent Jon Cohen that he couldn't fit it in any other place.

Many people in the United States trusted Fauci to guide them through COVID-19. The hero worship was evident in Fauci bobbleheads, yard signs, and baseball cards. Some of Trump's top advisers turned on Fauci. He was seen as a threat to the social order, the economy, and the health of the public because he was inconsistent and misleading. There are yard signs that say Fauci for Prison, T-shirts that say "even my dog hates Fauci", and ball caps that call him a fraud. He and his family have been the target of death threats, and his house has had a Secret Service detail protect it.

He wouldn't retire until there were vaccines for HIV, Malaria, and Tuberculosis. Fauci explained his change of mind, acknowledged some mistakes, and talked about what he might do next in an interview with Science. The interview has been edited to make it more concise and clear.

Q: What triggered your decision to leave at the end of this year? You had a much longer range view when we spoke in February 2021 for the AAAS meeting, and then you later said you would retire at the end of Biden’s first term.

I didn't say that I would retire at the end of Biden's first term. Go back and read what I have to say. I was asked if I would stay and work with Donald Trump if he became president. I said that it doesn't matter if he's the next president or if there's another Republican. I won't be here at the end of the day

I walked onto the National Institute of Health campus when I was 27 years old, after finishing my medical residency in New York. I have amassed a lot of experience. At the end of the discovery of an HIV vaccine, I wanted to be here to see it. We aren't going to get an HIV vaccine for another decade at least. I was making fun of myself when I said Malaria and Tuberculosis.

Q: You really haven’t answered the question precisely. Was it the threats to your three daughters and your wife? The attacks in the media and Congress? What is it that finally just made you say, I’m done with this job?

It wasn't the above. I don't lie to you because I know you well. I was considering wanting to have at least a few years when I am still passionate about doing something outside of the government. The president called me right after he was elected and asked me to be his chief medical adviser. At the end of the first year of the Biden administration, I thought that COVID would be in the back of my mind.

It became clear at the end of the year that that wouldn't happen. My wife told me that this is not going to go away. The wife of Fausto is the head of the bioethics division at the National Institute of Health. I asked myself, what do I have left to offer?

Donald Trump and Anthony Fauci at a COVID-19 taskforce press conference in March 2020
President Donald Trump (left) appointed Anthony Fauci to his administration’s Coronavirus Task Force, which held closely watched daily press conferences like this one on 31 March 2020.Jabin Botsford/The Washington Post via Getty Images

I have achieved a degree of being a hero to some people despite my weapons. Let me use that as motivation. I wanted to know when I could do that. The best time to do it is when you are getting used to the disease, so you can leave.

Q: Is some of the vitriol toward you about being a flip-flopper with your pandemic advice a result of having to make public health decisions in public in real time?

When you do an experiment, you collect data, validate it, scrub it, analyze it, and then write something that is based on science that is not dynamic, but is unchanging. The evolution of a process that has a lot of consequences because people's lives are involved is what you see when you deal with a Pandemic response. The public expects you to make daily statements about what to do. We were saying this a week, a month, 2 months ago, but now things have changed so much that it has been taken as flip-flops, being wrong, and making a mistake.

I am aware that the classic one is about masks. How many times are we going to look at that? The Centers for Disease Control and Prevention does not recommend buying masks. We don't know if it works outside of the health care setting Everyone is unaware of the aerosol spread. We didn't know that most of the transmissions were by someone who wasn't active. We shouldn't wear a mask. The facts changed as soon as possible. I said that we need to be wearing a mask indoors. That turns into flip-flops of arrogance.

Q: In retrospect, do you think you could have framed it more cautiously in the early days and said, we don’t really know enough right now, it doesn’t look like we need masks, and there’s a shortage of N95s?

That is not what people would like to hear. They would like to know what we should do. I should have couched it in a way that allowed for flexibility. I can tell you that if I did, I would have been labeled a wallflower, because he didn't know what he was talking about.

Q: So what are you going to do? You’ve said you’re going to write a memoir. You’ve never been much motivated by money.

I would have taken 100 jobs if I were motivated by money.

Jon, I don't know and I'm very honest with you. I will let you know what I did. I went to the Office of the General Counsel and asked what I could do after I retire. If you want to stay pristine, you have to leave. No one can accuse you of giving out little signals about what you are going to do. Is it because you are so skeptical at me?

Q: I just imagine you have some dreams.

I am not sure what that will be. It is possible that I will be made a senior professor at the university. Maybe it's going with a foundation. I won't do one thing. I won't be sitting in my house with a email address.

Q: You’ve published more than 1100 papers. Your first one was in 1965 on celiac disease, and then over the next 15 years, you published 62 papers on Wegener’s granulomatosis. That could have been your career. You never broke into Nature or Science with those papers. It isn’t until AIDS surfaced that you started regularly publishing in high-impact journals. You were already well into your career before you found what became your deep passion and focus.

It turned me around when I began to see gay men who were dying. It moved me so much that I didn't know what to think. I made a decision to pivot. I had a successful career that got me into most of the societies, the young Turks, the old Turks, but then I said that I wanted to devote my career to this. I took care of very sick people who had HIV from the fall of 1981 until the fall of 1982. I have a passion for learning about this disease. That is the reason why I am fanatically obsessed with researching on that.

Anthony Fauci and treatment team with an early AIDS patient at NIH, 1987
Caring for AIDS patients, such as this man at the National Institutes of Health Clinical Center in 1987, shifted Anthony Fauci’s focus to infectious diseases.NIAID/Alamy

Q: Looking back, who was the easiest president to work with? I know who the most difficult one was.

Someone wouldn't want to say who was the easiest. They were not the same as one another. The differences were dictated by the circumstances of their presidency. I was very close to George H.W. Bush. A good man. The chief architect of the President's Emergency Plan for AIDS Relief was me. The most important thing I have done is PEPFAR. More than 50 countries have been helped byPEPFAR in preventing and treating HIV. I wouldn't have been able to do what I did if the president hadn't trusted me.

Anthony Fauci is presented the Medal of Freedom by President George W. Bush in 2008
Anthony Fauci started the President’s Emergency Plan for AIDS Relief, which helped supply countries with HIV drugs, with support from President George W. Bush (right), who awarded him the Presidential Medal of Freedom in 2008.AFP PHOTO/Karen BLEIER

Q: Do you think NIH directors should stay in the same position for decades, the way you have? Or should NIH set term limits?

It should be able to change. It is dependent on the individual and what is happening. I don't think those statements are valid. Every four years, you should be evaluated by an outside group. I support longevity based on performance.

Q: Do you have any advice for NIH about who they should look for or what type of person?

A person but not a person is not appropriate. You need someone who understands the science. You will be involved in the next outbreak and the next public health crisis if you don't know how to navigate the public exposure.

Q: What do you want to accomplish between now and December?

I want to guide the good research being done in the area of both mucosal, nasal vaccines for respiratory diseases, as well as more durable vaccines that protect against entire families of Viruses. I like to push people. We meet as a group at least three times a week and I don't know what we're doing. I don't want to be a pain in the ass but I want to keep that thing going between now and then.

Q: I’ve seen loads of people confront you over more than 30 years. No one seems to get under your skin as much as Senator Rand Paul (R–KY). Why does that guy piss you off so much? [Paul has accused Fauci of helping trigger the pandemic by funding scientists in Wuhan, China, whom Paul and others allege either created SARS-CoV-2 or had an accidental lab leak of a bat virus they had collected.]

I came into an oversight hearing where politicians asked questions to improve the situation and protect the health of the country. How do you explain to the public that you are responsible for the deaths of 5 million people? I will not stand for that on public TV. I'm sorry, Jon. It's not possible.

Q: You got into a debate with him about the meaning of gain of function. [The Wuhan scientists combined a bat coronavirus growing in culture with a piece from another one, and the chimeric virus, in mouse experiments, was more deadly than the original one—but it could not have been used to create SARS-CoV-2.] The Tony Fauci I know, who’s very calm under pressure, would have said, yes, the virus in this experiment gained some function, but that’s not what we’re talking about here. We’re talking about whether it met a definition of gain of function that put the public at risk.

You're correct. I wouldn't have done it the same way if I had to do it again. I should have said that was irrelevant to the safety of the country. He called me a murderer, and it shocked me. I should have said, "This guy is a jerk"

The AIDS activists attacked me in the ’80s, but that kind of attack is different now. They were talking about real suffering to get my attention. They wanted me to listen to those who were hurting when they put my head on a spike. I was able to hear them. It was the best thing I have ever done. I didn't get angry with them.

Anthony Fauci responds to accusations by Sen. Rand Paul, R-KY, as he testifies during the Senate Health, Education, Labor, and Pensions Committee hearing on Capitol Hill in Washington,DC on July 20, 2021.
Anthony Fauci at a Senate hearing on 20 July had a contentious showdown with Senator Rand Paul (R–KY).J. SCOTT APPLEWHITE/POOL/AFP via Getty Images

Q: If the House of Representatives becomes Republican-majority, and they hold hearings, will you testify?

I'll testify if I'm asked to. I don't have to say anything. I can defend everything I have done. If it is clear that it is a character assassination, I may not play ball.

Q: A last question for you. Do you have a motto that you told your kids, like, this is what I learned in life?

It's what I do. It's called precision of thought. Know what you're talking about, know your audience, and say it in a few words.