On June 5, 1981, the Centers for Disease Control and Prevention published a brief, clinical report in its Morbidity and Mortality Weekly Report about five young men in Los Angeles who had developed a rare and deadly form of pneumonia. 

The write-up, barely a page long, ran in between a report on dengue infections among US travelers and an assessment of measles cases. No one who read it could have known this was the opening chapter of the deadliest infectious disease epidemic since the 1918 flu — one that would kill an estimated 44 million people worldwide and reshape medicine, politics, and culture in ways we’re still reckoning with. It would eventually be called human immunodeficiency virus, or HIV.

For the next 15 years, an HIV diagnosis was, functionally, a death sentence, as the immune system was hollowed out on a slow march to full-blown AIDS. The virus mutated so rapidly that every early attempt at treatment felt like trying to hit a moving target in the dark. And the dark was where many of the earliest victims were forced to live, stigmatized by society. It took until September 1985 for President Ronald Reagan to even say the word “AIDS” publicly, by which point some 6,000 Americans had already died. 

By 1993, HIV had become the leading cause of death for all Americans aged 25 to 44. Not just gay men. Not just intravenous drug users. Everyone in the prime of their lives. In 1995, at the epidemic’s American peak, 50,628 people died of AIDS in a single year. Globally, new infections peaked the following year at around 3.4 million. In the hardest-hit cities of sub-Saharan Africa,  one in five adults were HIV positive. Entire generations of parents were being wiped out. By 2000, AIDS was the leading cause of death on the African continent.

The story could have ended there: The virus had won while the world looked away. But it didn’t. What happened instead, through a combination of activist fury, scientific ingenuity, and an act of bipartisan political will that still seems improbable in hindsight, is one of the great reversals in the history of medicine. It’s a narrative that provides hope not just that we might one day get to zero and eradicate HIV, but that the world can overcome what may seem like the most hopeless challenges. 

Miracle drugs — and a community that wouldn’t die

For the first decade of the epidemic, the US government’s response was defined by indifference, until activists decided to make that impossible. The group Act Up turned unimaginable grief into political force, storming the Food and Drug Administration, shutting down Wall Street, and transforming funerals into protests. They were loud and furious and provocative — and effective: Act Up and allied organizations pressured the FDA into creating accelerated drug approval pathways and shamed pharmaceutical companies into expanding access to experimental HIV treatments.

The clinical turning point came at the 1996 International AIDS Conference in Vancouver. Researchers including Dr. David Ho presented data on combination antiretroviral therapy — what would become known as HAART. Scientists combined multiple drugs into a cocktail that attacked HIV at different stages of its life cycle — basically surrounding the virus so it had nowhere to evolve to.

The results were staggering: 60 percent to 80 percent declines in rates of AIDS, death, and hospitalization. Patients who had been days from death recovered so dramatically that doctors called it the “Lazarus effect.” One physician’s practice went from 37 patient deaths in 1995 to zero in 1998. Nationally, AIDS deaths in the United States fell 63 percent in three years. HIV dropped from the No. 1 killer of young Americans to No. 5 by 1997 — an unprecedented decline for any leading cause of death in modern history.

But the Lazarus effect had a brutal asterisk. Early antiretroviral therapy cost $10,000 to $15,000 per patient per year. For most Americans with HIV, that was doable with a mix of insurance and government funding. For the tens of millions infected in impoverished sub-Saharan Africa — where the epidemic was orders of magnitude worse than in the West — those lifesaving drugs were all but unobtainable. In January 2003, nearly a decade after antiretrovirals had become widespread in the US, only about 50,000 people in all of sub-Saharan Africa were on the drugs. Thirty million were infected. Roughly 12 million Africans died of AIDS between 1997 and 2006 while high costs and supply bottlenecks kept the treatment that would have saved their lives out of reach.

It’s not hard to imagine an alternate history where this inequality of death persisted. After all, we implicitly accept this ingrained inequality in so many other areas, from extreme poverty to childhood mortality. 

But that’s not what happened. The same activist energy that had forced the FDA’s hand in the 1990s turned its attention to the global treatment gap, joined by an unlikely alliance of evangelical Christians motivated by faith, public health officials who saw a security threat, and a president who cited the parable of the Good Samaritan.

During his 2003 State of the Union address, President George W. Bush pledged $15 billion over five years to fight AIDS abroad through what he called the President’s Emergency Plan for AIDS Relief, or PEPFAR. The House passed the legislation that created PEPFAR 375-41, a sign of just how broad the coalition behind it was. 

In April 2004, a 34-year-old man in Uganda named John Robert Engole became the first person in the world to receive PEPFAR-supported antiretroviral therapy. By the end of 2005, some 400,000 people were on treatment through the program. By 2008, it was 2 million around the world — a 40-fold increase from the 50,000 Africans on ART when Bush made his speech. 

PEPFAR has since invested over $120 billion and, by its own estimates, saved 26 million lives. The cost of treating one patient in a low-income country fell from roughly $1,200 a year in 2003 to $58 by 2023. As my former colleague Dylan Matthews once wrote, PEPFAR is “one of the best government programs in American history.”

Winning the war

The downstream effects of PEPFAR and other advances in HIV treatment and prevention are extraordinary. 

Annual global AIDS deaths have fallen from a peak of 2.1 million in 2004 to 630,000 in 2024 — a 70 percent reduction. Some 30.7 million people in low- and middle-income countries are now on antiretroviral therapy worldwide, up from fewer than 400,000 just two decades ago. That’s nearly an 80-fold increase. 

What this all means is that someone diagnosed with HIV today who gets on treatment can expect a near-normal lifespan, which is an outcome that would have been literally unimaginable to anyone living through the 1980s and early 1990s.

On top of far better treatment, the toolkit for preventing people from getting HIV in the first place has become far more effective, which has helped lead new infections to drop more than 60 percent from 3.4 million in 1996 to 1.3 million. PrEP — a daily pill that reduces the risk of contracting HIV by up to 99 percent — has been available since 2012, and more than 3.5 million people around the world have taken it at least once. Last year the FDA approved lenacapavir, a twice-yearly injection that Science magazine named its 2024 breakthrough of the year. In the PURPOSE 1 trial of the drug, among more than 2,100 women in South Africa and Uganda, there were zero HIV infections. Not a low number. Zero.

HIV treatment, essentially, has become so effective that it now acts as prevention as well. HIV experts call it Undetectable equals Untransmittable, or U=U. Studies encompassing over 100,000 acts of condomless sex where one partner is HIV positive and another is not have found zero linked transmissions. That means someone living with HIV who is virally suppressed cannot pass the virus on sexually, which is a step toward both normalizing a disease that was once so feared and further curtailing the epidemic. And these tools can work at scale: The SEARCH trial showed that community health workers in rural Kenya and Uganda, armed with smartphone apps and the ability to immediately provide antiretroviral treatment to anyone testing positive, cut new infections by 70 percent.

The backlash that could kill

And yet, more than 630,000 people still die of AIDS every year — roughly one every minute. Some 9.2 million people who need treatment still aren’t getting it. Children are the worst off: only 55 percent of those under 14 with HIV are on therapy, compared to 78 percent of adults. And the epidemic’s burden falls hardest on the most marginalized: sex workers, men who have sex with men, people who inject drugs, and transgender people now account for over 55 percent of all new infections globally — up from 44 percent in 2010.

Two-thirds of all people living with HIV are in sub-Saharan Africa, where external funding finances around 80 percent of prevention programs. That has left them vulnerable as the global HIV response faces its gravest funding threat in decades. 

PEPFAR’s statutory authorization lapsed in March 2025 without congressional reauthorization. A January 2025 stop-work order froze programs worldwide. The effective dismantling of USAID — with 90 percent of contracts canceled — has gutted the program’s infrastructure. UNAIDS modeling suggests that if these disruptions become permanent, the result could be 6 million additional infections and 4 million additional deaths by 2029. South Africa alone has already laid off some 8,000 health care workers because of funding cuts.

And the threat isn’t only abroad: More than 20 US states are now considering cuts to the AIDS Drug Assistance Program, the safety net that covers a quarter of all Americans living with HIV — including Florida, where 16,000 people briefly lost coverage before an emergency fix that lasts only through the summer. A recent Johns Hopkins study estimated that eliminating the program’s parent legislation could increase new infections in major US cities by nearly 50 percent by 2030

For the first time in the 45-year history of this epidemic, we have genuinely effective tools to end it: drugs that treat, pills and injections that prevent, even hopes for a potential vaccine. The gap between where we are and where we need to be is no longer a question of science. It is a question of money and political will — the same forces that, two decades ago, helped produce the most effective global health program in American history. 

The story of HIV is a story of what humanity can accomplish when it decides something matters enough. We’ve made that decision before. The question is whether we’ll make it again.

A version of this story originally appeared in the Good News newsletter. Sign up here!

On February 9, 1970, Johnny Carson did something that would be unthinkable for a late night host today, or really anyone on TV: He gave a full hour of The Tonight Show to a Stanford professor.

But Paul Ehrlich, the author along with his wife Anne of the blockbuster book The Population Bomb, was charismatic, telegenic, and absolutely terrifying. He told Carson’s massive audience that hundreds of millions of people were about to starve to death. Nothing could stop it.

Ehrlich’s first appearance on The Tonight Show demonstrates a lot of things, not least how much popular TV has changed. (I’m struggling to imagine Carson’s eventual successor Jimmy Fallon giving an hour to, say, CRISPR inventor Jennifer Doudna — and without even doing a lip sync battle.) But it also shows just how influential Ehrlich was.

He would go on The Tonight Show more than 20 times. The Population Bomb sold over 2 million copies and became one of the most popular science books of the 20th century. His work helped popularize a broader population-panic worldview that influenced policymakers in the US and abroad, including coercive family-planning policies in countries such as India and China. Ehrlich and his book fundamentally changed the world we live in today.

And yet Ehrlich, who died last week at 93, turned out to be spectacularly wrong, wrong in ways that had major consequences for humanity. But precisely because he was wrong and yet so influential, understanding why his views were so popular is necessary for understanding why doomsaying remains so seductive — and so dangerous. 

The book that went off like a bomb

The Population Bomb, I suspect, was one of those of-the-moment books that was more owned than read. But you didn’t need to get far into it to grasp Ehrlich’s alarmist message. You just needed to read the opening lines: “The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.”

And the book was just part of his lifelong campaign. Ehrlich predicted that 65 million Americans would die of famine between 1980 and 1989. He told a British audience that by the year 2000, the United Kingdom would be “a small group of impoverished islands, inhabited by some 70 million hungry people.” He said India — which was home to nearly 600 million people in 1970 — could never feed 200 million more people. He said US life expectancy would drop to 42 by 1980. On Earth Day 1970, he declared that “in 10 years all important animal life in the sea will be extinct.”

Every one of these predictions was almost 180 degrees in the wrong direction. In America, as in much of the world, obesity became the true metabolic health crisis, not starvation. The UK — at least the last time I checked — still exists. India is now a major agricultural exporter, and its population has nearly tripled while hunger has fallen. Marine life is stressed but very much not extinct.

The bottom line is that instead of mass starvation, the world experienced the greatest expansion of food production in human history. Global cereal production today exceeds 3 billion tonnes, a roughly threefold increase from 1970. Per capita calorie supply has risen consistently since 1961. Since The Population Bomb was published, rates of hunger have dropped precipitously. 

When the wrong lines go up

What did Ehrlich miss? For one thing, he made a common mistake: He assumed “line go up.” 

The years leading up to The Population Bomb’s publication in 1968 featured the steepest population increases in global history. The trends were so on the nose for his thesis that you could almost forgive Ehrlich for assuming they would inevitably continue.

But a closer look at the data would have revealed that even in the high-growth 1960s, the world was already beginning a demographic transition that would lead us to our comparatively low-fertility present. Europe, Japan, and North America were all seeing their fertility rates fall as societies urbanized, women were educated, and child mortality dropped. The theories explaining that demographic transition were already decades old by 1968, which was also eight years after the birth control pill was introduced.

Ehrlich — and many others of his time, to be fair — appeared to assume that these patterns wouldn’t apply as the countries of the Global South developed. But they did. As these social and economic trends spread around the world, fertility kept falling, from around five children per woman globally when The Population Bomb was published to 2.3 today, which is barely above the population replacement rate of 2.1.

But the bigger mistake wasn’t misreading demographics. It was failing to account for people like Norman Borlaug.

Borlaug was an agronomist from rural Iowa who, with the support of the Rockefeller Foundation, developed high-yielding dwarf wheat varieties that transformed agriculture in countries like Mexico, India, and Pakistan. India, which Ehrlich had written off in racially tinged ways, didn’t just avoid famine; it became self-sufficient in food production.

The Population Bomb was explicit about Ehrlich’s worldview: Population growth was “the cancer” that “must be cut out.” He saw people — or at least, people in the Global South — as little more than mouths to feed, each fighting for shares of a static pie. Borlaug and the Green Revolution researchers, by contrast, saw them as minds to solve problems, including figuring out ways to make the pie bigger. Ehrlich’s fundamentally zero-sum worldview may have gotten him global recognition — and sadly, remains far too prevalent — but it blinded him to the future.

And that’s why he ended up on the losing end of one of the most famous wagers in academic history. 

The bet that explains the world

Julian Simon, an economist at the University of Maryland, believed the opposite of everything Ehrlich believed. Simon’s argument was simple: People are the world’s most valuable resource. Human ingenuity responds to scarcity by finding new supplies, substitutes, and efficiencies. And that meant that commodity prices, adjusted for inflation, would fall over time — not rise.

In 1980, Simon challenged Ehrlich to a bet: Pick any raw materials, any time period longer than a year, and wager on whether prices would go up or down. Ehrlich and two colleagues chose five metals — chromium, copper, nickel, tin, and tungsten — and bought $1,000 worth on paper. The bet would be settled in 1990. During those 10 years, the world’s population grew by more than 800 million — the largest one-decade increase in human history.

Ehrlich was wrong. (Again.) All five metals fell in inflation-adjusted price. In October 1990, Ehrlich acknowledged Simon’s win with a check for $576.07.

What Ehrlich didn’t do was revise his views to reflect the facts, which is what makes him more than a cautionary tale about bad predictions. In 2009 he told an interviewer that The Population Bomb was “way too optimistic.” In 2015 he said his language “would be even more apocalyptic today.” On 60 Minutes in 2023, at age 90, he told Scott Pelley that “the next few decades will be the end of the kind of civilization we’re used to.”

It didn’t matter that the world had spent 55 years proving him wrong. Ehrlich didn’t blink.

And Ehrlich’s wrongness had real consequences. He endorsed cutting off food aid to countries he considered hopeless, including India and Egypt. The broader population-panic movement Ehrlich helped create influenced coercive real-world policies: India’s forced sterilization campaigns during the 1970s, China’s one-child policy, and sterilization programs across the developing world.

The dangerous appeal of doomsaying

So why did the world listen for so long? Partly because we’re wired to. As readers of this newsletter know, humans process negative information more readily than positive, an evolutionary hangover that makes doomsayers inherently more compelling than optimists. And Philip Tetlock’s research on expert prediction found that “hedgehog” thinkers — people who, like Ehrlich, see everything through the lens of one big idea, and fight like hell to hold onto it — are simultaneously the worst forecasters but get the most media attention. They’re more confident, more quotable, more dramatic. The hedgehog gets Carson. The fox gets ignored.

There’s also a structural incentive problem. Predict things will be fine and you’re wrong? You’re irresponsible. Predict disaster and you’re right? You’re a genius. Predict disaster and you’re wrong? People forget — or just assume you were a little early. (It was notable to me that the subheadline of the New York Times obituary of Ehrlich called his predictions not wrong, but “premature.”)

None of this means we should ignore environmental problems. Climate change is real, and Ehrlich was relatively early in flagging it. Biodiversity loss — closer to his actual academic expertise in entomology — remains genuinely alarming. And we shouldn’t repeat Ehrlich’s mistakes in the opposite direction. Just because things have been getting better does not automatically mean that trend will continue, especially if we make perverse and self-defeating policy choices.

But the real lesson of Ehrlich’s life is that assuming doom leads to worse policy than assuming agency. Write off a country as hopeless, and you justify cutting its food aid. Assume people are the problem, and you end up sterilizing them against their will.

Julian Simon died in 1998, never approaching Ehrlich’s level of public fame. His signature line: “The ultimate resource is people — skilled, spirited, and hopeful people who will exert their wills and imaginations for their own benefit as well as in a spirit of faith and social concern.”

That might not have played as well on The Tonight Show. But it’s the formula for a much better world.