I am no longer a professor of medicine at Harvard. The Harvard motto is Veritas, Latin for truth. But, as I discovered, truth can get you fired. This is my story—a story of a Harvard biostatistician and infectious-disease epidemiologist, clinging to the truth as the world lost its way during the Covid pandemic.

On March 10, 2020, before any government prompting, Harvard declared that it would “suspend in-person classes and shift to online learning.” Across the country, universities, schools, and state governments followed Harvard’s lead.

Yet it was clear, from early 2020, that the virus would eventually spread across the globe, and that it would be futile to try to suppress it with lockdowns. It was also clear that lockdowns would inflict enormous collateral damage, not only on education but also on public health, including treatment for cancer, cardiovascular disease, and mental health. We will be dealing with the harm done for decades. Our children, the elderly, the middle class, the working class, and the poor around the world—all will suffer.

Schools closed in many other countries, too, but under heavy international criticism, Sweden kept its schools and daycares open for its 1.8 million children, ages one to 15. Why? While anyone can get infected, we have known since early 2020 that more than a thousandfold difference in Covid mortality risk holds between the young and the old. Children faced minuscule risk from Covid, and interrupting their education would disadvantage them for life, especially those whose families could not afford private schools, pod schools, or tutors, or to homeschool.

What were the results during the spring of 2020? With schools open, Sweden had zero Covid deaths in the one-to-15 age group, while teachers had the same mortality as the average of other professions. Based on those facts, summarized in a July 7, 2020, reportby the Swedish Public Health Agency, all U.S. schools should have quickly reopened. Not doing so led to “startling evidence on learning loss” in the United States, especially among lower- and middle-class children, an effect not seen in Sweden.

Sweden was the only major Western country that rejected school closures and other lockdowns in favor of concentrating on the elderly, and the final verdict is now in. Led by an intelligent social democrat prime minister (a welder), Sweden had the lowest excess mortality among major European countries during the pandemic, and less than half that of the United States. Sweden’s Covid deaths were below average, and it avoided collateral mortality caused by lockdowns.

Yet on July 29, 2020, the Harvard-edited New England Journal of Medicine published an article by two Harvard professors on whether primary schools should reopen, without even mentioning Sweden. It was like ignoring the placebo control group when evaluating a new pharmaceutical drug. That’s not the path to truth.

That spring, I supported the Swedish approach in op-eds published in my native Sweden, but despite being a Harvard professor, I was unable to publish my thoughts in American media. My attempts to disseminate the Swedish school report on Twitter (now X) put me on the platform’s Trends Blacklist. In August 2020, my op-ed on school closures and Sweden was finally published by CNN—but not the one you’re thinking of. I wrote it in Spanish, and CNN–Español ran it. CNN–English was not interested.

I was not the only public health scientist speaking out against school closures and other unscientific countermeasures. Scott Atlas, an especially brave voice, used scientific articles and facts to challenge the public health advisors in the Trump White House, National Institute of Allergy and Infectious Diseases director Anthony Fauci, National Institutes of Health director Francis Collins, and Covid coordinator Deborah Birx, but to little avail. When 98 of his Stanford faculty colleagues unjustly attacked Atlas in an open letter that did not provide a single example of where he was wrong, I wrote a response in the student-run Stanford Daily to defend him. I ended the letter by pointing out that:

Among experts on infectious disease outbreaks, many of us have long advocated for an age-targeted strategy, and I would be delighted to debate this with any of the 98 signatories. Supporters include Professor Sunetra Gupta at Oxford University, the world’s preeminent infectious disease epidemiologist. Assuming no bias against women scientists of color, I urge Stanford faculty and students to read her thoughts.

None of the 98 signatories accepted my offer to debate. Instead, someone at Stanford sent complaints to my superiors at Harvard, who were not thrilled with me.

I had no inclination to back down. Together with Gupta and Jay Bhattacharya at Stanford, I wrote the Great Barrington Declaration, arguing for age-based focused protection instead of universal lockdowns, with specific suggestions for how better to protect the elderly, while letting children and young adults live close to normal lives.

With the Great Barrington Declaration, the silencing was broken. While it is easy to dismiss individual scientists, it was impossible to ignore three senior infectious-disease epidemiologists from three leading universities. The declaration made clear that no scientific consensus existed for school closures and many other lockdown measures. In response, though, the attacks intensified—and even grew slanderous. Collins, a lab scientist with limited public-health experience who controls most of the nation’s medical research budget, called us “fringe epidemiologists” and asked his colleagues to orchestrate a “devastating published takedown.” Some at Harvard obliged.

A prominent Harvard epidemiologist publicly called the declaration “an extreme fringe view,” equating it with exorcism to expel demons. A member of Harvard’s Center for Health and Human Rights, who had argued for school closures, accused me of “trolling” and having “idiosyncratic politics,” falsely alleging that I was “enticed . . . with Koch money,” “cultivated by right-wing think tanks,” and “won’t debate anyone.” (A concern for those less privileged does not automatically make you right-wing!) Others at Harvard worried about my “scientifically inaccurate” and “potentially dangerous position,” while “grappling with the protections offered by academic freedom.”

Though powerful scientists, politicians, and the media vigorously denounced it, the Great Barrington Declaration gathered almost a million signatures, including tens of thousands from scientists and health-care professionals. We were less alone than we had thought.

Even from Harvard, I received more positive than negative feedback. Among many others, support came from a former chair of the Department of Epidemiology—a former dean, a top surgeon, and an autism expert, who saw firsthand the devastating collateral damage that lockdowns inflicted on her patients. While some of the support I received was public, most was behind the scenes from faculty unwilling to speak publicly.

Two Harvard colleagues tried to arrange a debate between me and opposing Harvard faculty, but just as with Stanford, there were no takers. The invitation to debate remains open. The public should not trust scientists, even Harvard scientists, unwilling to debate their positions with fellow scientists.

My former employer, the Mass General Brigham hospital system, employs the majority of Harvard Medical School faculty. It is the single largest recipient of NIH funding—over $1 billion per year from U.S. taxpayers. As part of the offensive against the Great Barrington Declaration, one of Mass General’s board members, Rochelle Walensky, a fellow Harvard professor who had served on the advisory council to NIH director Collins, engaged me in a one-directional “debate.” After a Boston radio station interviewed me, Walensky came on as the official representative of Mass General Brigham to counter me, without giving me an opportunity to respond. A few months later, she became the new CDC director.

At this point, it was clear that I faced a choice between science or my academic career. I chose the former. What is science if we do not humbly pursue the truth?

In the 1980s, I worked for a human rights organization in Guatemala. We provided round-the-clock international physical accompaniment to poor campesinos, unionists, women’s groups, students, and religious organizations. Our mission was to protect those who spoke up against the killings and disappearances perpetrated by the right-wing military dictatorship, which shunned international scrutiny of its dirty work. Though the military threatened us, stabbed two of my colleagues, and threw a hand grenade into the house where we all lived and worked, we stayed to protect the brave Guatemalans.

I chose then to risk my life to help protect vulnerable people. It was a comparatively easy choice to risk my academic career to do the same during the pandemic. While the situation was less dramatic and terrifying than the one that I faced in Guatemala, many more lives were ultimately at stake.

While school closures and lockdowns were the big controversy of 2020, a new dispute emerged in 2021: the Covid vaccines. For more than two decades, I have helped the CDC and FDA develop their post-market vaccine safety systems. Vaccines are a vital medical invention, allowing people to obtain immunity without the risk that comes from getting sick. The smallpox vaccine alone has saved millions of lives. In 2020, the CDC asked me to serve on its Covid-19 Vaccine Safety Technical Work Group. My tenure didn’t last long—though not for the reason you may think.

The randomized controlled trials (RCTs) for the Covid vaccines were not properly designed. While they demonstrated the vaccines’ short-term efficacy against symptomatic infection, they were not designed to evaluate hospitalization and death, which is what matters. In subsequent pooled RCT analyses by vaccine type, independent Danish scientists showed that the mRNA vaccines (Pfizer and Moderna) did not reduce short-term, all-cause mortality, while the adenovirus-vector vaccines (Johnson & Johnson, Astra-Zeneca, Sputnik) did reduce mortality, by at least 30 percent.

I have spent decades studying drug and vaccine adverse reactions without taking any money from pharmaceutical companies. Every honest person knows that new drugs and vaccines come with potential risks that are unknown when approved. This was a risk worth taking for older people at high risk of Covid mortality—but not for children, who have a minuscule risk for Covid mortality, nor for those who already had infection-acquired immunity. To a question about this on Twitter in 2021, I responded:

Thinking that everyone must be vaccinated is as scientifically flawed as thinking that nobody should. COVID vaccines are important for older high-risk people and their care-takers. Those with prior natural infection do not need it. Nor children.

At the behest of the U.S. government, Twitter censored my tweet for contravening CDC policy. Having also been censored by LinkedIn, Facebook, and YouTube, I could not freely communicate as a scientist. Who decided that American free-speech rights did not apply to honest scientific comments at odds with those of the CDC director?

I was tempted just to shut up, but a Harvard colleague convinced me otherwise. Her family had been active against Communism in Eastern Europe, and she reminded me that we needed to use whatever openings we could find—while self-censoring, when necessary, to avoid getting suspended or fired.

On that score, however, I failed. A month after my tweet, I was fired from the CDC Covid Vaccine Safety Working Group—not because I was critical of vaccines but because I contradicted CDC policy. In April 2021, the CDC paused the J&J vaccine after reports of blood clots in a few women under 50. No cases were reported among older people, who benefit the most from the vaccine. Since there was a general vaccine shortage at that time, I argued in an op-ed that the J&J vaccine should not be paused for older Americans. This is what got me in trouble. I am probably the only person ever fired by the CDC for being too pro-vaccine. While the CDC lifted the pause four days later, the damage was done. Some older Americans undoubtedly died because of this vaccine “pause.”

Bodily autonomy is not the only argument against Covid vaccine mandates. They are also unscientific and unethical.

With a genetic condition called alpha-1 antitrypsin deficiency, which leaves me with a weakened immune system, I had more reason to be personally concerned about Covid than most Harvard professors. I expected that Covid would hit me hard, and that’s precisely what happened in early 2021, when the devoted staff at Manchester Hospital in Connecticut saved my life. But it would have been wrong for me to let my personal vulnerability to infections influence my opinions and recommendations as a public-health scientist, which must focus on everyone’s health.

The beauty of our immune system is that those who recover from an infection are protected if and when they are re-exposed. This has been known since the Athenian Plague of 430 BC—but it is no longer known at Harvard. Three prominent Harvard faculty coauthored the now infamous “consensus” memorandum in The Lancet, questioning the existence of Covid-acquired immunity. By continuing to mandate the vaccine for students with a prior Covid infection, Harvard is de facto denying 2,500 years of science.

Since mid-2021, we have known, as one would expect, that Covid-acquired immunity is superior to vaccine-acquired immunity. Based on that, I argued that hospitals should hire, not fire, nurses and other hospital staff with Covid-acquired immunity, since they have stronger immunity than the vaccinated.

Vaccine mandates are unethical. The RCTs mainly enrolled young and middle-aged adults, but observational studies showed that Covid vaccines prevented Covid hospitalizations and deaths for older people. Amid a worldwide vaccine shortage, it was unethical to force the vaccine on low-risk students or those like me who were already immune from having had Covid, while my 87-year-old neighbor and other high-risk older people around the world could not get the shot. Any pro-vaccine person should, for this reason alone, have opposed the Covid vaccine mandates.

For scientific, ethical, public health, and medical reasons, I objected both publicly and privately to the Covid vaccine mandates. I already had superior infection-acquired immunity; and it was risky to vaccinate me without proper efficacy and safety studieson patients with my type of immune deficiency. This stance got me fired by Mass General Brigham—and consequently fired from my Harvard faculty position.

While several vaccine exemptions were given by the hospital, my medical exemption request was denied. I was less surprised that my religious exemption request was denied: “Having had COVID disease, I have stronger longer lasting immunity than those vaccinated (Gazit et al). Lacking scientific rationale, vaccine mandates are religious dogma, and I request a religious exemption from COVID vaccination.”

If Harvard and its hospitals want to be credible scientific institutions, they should rehire those of us they fired. And Harvard would be wise to eliminate its Covid vaccine mandates for students, as most other universities have already done.

Most Harvard faculty diligently pursue truth in a wide variety of fields, but Veritas has not been the guiding principle of Harvard leaders. Nor have academic freedom, intellectual curiosity, independence from external forces, or concern for ordinary people guided their decisions.

Harvard and the wider scientific community have much work to do to deserve and regain public trust. The first steps are the restoration of academic freedom and the cancelling of cancel culture. When scientists have different takes on topics of public importance, universities should organize open and civilized debates to pursue the truth. Harvard could have done that—and it still can, if it chooses.

Almost everyone now realizes that school closures and other lockdowns, were a colossal mistake. Francis Collins has acknowledged his error of singularly focusing on Covid without considering collateral damage to education and non-Covid health outcomes. That’s the honest thing to do, and I hope this honesty will reach Harvard. The public deserves it, and academia needs it to restore its credibility.

Science cannot survive in a society that does not value truth and strive to discover it. The scientific community will gradually lose public support and slowly disintegrate in such a culture. The pursuit of truth requires academic freedom with open, passionate, and civilized scientific discourse, with zero tolerance for slander, bullying, or cancellation. My hope is that someday, Harvard will find its way back to academic freedom and independence.