Stuff That Used to Kill Millions Now Barely Exists

Let me walk you through a list of things that used to terrify the entire human species and are now either gone, nearly gone, or so thoroughly managed that most people under 40 have never given them a second thought.

Smallpox: Erased

Smallpox killed an estimated 300 million people in the 20th century alone. Three hundred million. It killed pharaohs. It killed kings. It killed Roman emperors. It wiped out an estimated 90% of the indigenous population of the Americas after European contact — not through war, but through a virus they had no immunity to. It was humanity's longest-running nightmare, a disease so feared that entire civilizations organized their spiritual lives around trying to appease whatever gods they believed sent it.

In 1980, after a decades-long global vaccination campaign coordinated by the WHO, smallpox was declared eradicated. Gone. Zero cases. The first — and still only — human disease ever eliminated from the planet by deliberate human effort. The last known natural case was in Somalia in 1977. An entire disease, one that had killed hundreds of millions of people across millennia, was wiped from existence by human ingenuity and cooperation.

Polio: Almost Gone

Polio paralyzed hundreds of thousands of children per year in the 1950s. In the United States, the summer polio season was a source of genuine terror for parents — swimming pools were closed, children were kept indoors, iron lung wards filled hospital after hospital. The Salk vaccine in 1955 and the Sabin oral vaccine in 1961 changed everything. In the U.S., polio cases dropped from about 58,000 per year to essentially zero within a decade.

Globally, wild poliovirus cases have fallen from an estimated 350,000 per year in 1988 to fewer than 15 in 2023 (WHO Global Polio Eradication Initiative). The disease now exists in only two countries — Afghanistan and Pakistan — and even there, case counts are in the single digits. We are within striking distance of making polio the second disease humanity has deliberately erased from existence.

Measles, HIV, and Malaria

Measles killed 2.6 million people per year in 1980. By 2019, that number had fallen to about 207,000 — a 92% reduction — thanks to vaccination (WHO). Still too many, yes. But 92% fewer than forty-five years ago. Before the vaccine, measles was considered an inevitable childhood disease. Now it's preventable with a shot that costs less than a dollar.

HIV/AIDS was a death sentence in the 1980s. If you're old enough to remember the early AIDS crisis, you remember the fear — the obituary pages filled with young men, the panic, the stigma, the absolute helplessness of watching people waste away from a disease nobody understood and nobody could treat. Today, antiretroviral therapy allows people with HIV to live near-normal lifespans. Many have undetectable viral loads, meaning they can't transmit the virus. Deaths from AIDS peaked at about 1.8 million in 2004 and have been cut by more than 60% (UNAIDS). A disease that once terrified the entire world has been transformed from a killer into a manageable chronic condition within one generation.

Malaria still kills — mostly children in sub-Saharan Africa — but deaths have been cut nearly in half since 2000, from about 900,000 per year to around 600,000 (WHO World Malaria Report). Insecticide-treated bed nets, which cost about $2 each, are one of the most cost-effective lifesaving interventions ever devised. And in 2021, the WHO approved the first malaria vaccine — RTS,S — for use in children, with a more effective second-generation vaccine (R21) approved in 2023. After a century of trying, we finally have vaccines against one of humanity's oldest killers.

Cancer and Heart Disease

Cancer survival rates have improved dramatically and continue to improve. The five-year survival rate for all cancers combined in the U.S. has risen from about 49% in the mid-1970s to around 68% today (National Cancer Institute SEER data). For some cancers — childhood leukemia, testicular cancer, certain lymphomas — survival rates are now above 90%. Immunotherapy, which harnesses the body's own immune system to fight tumors, is producing remissions in cancers that were untreatable ten years ago. CAR-T cell therapy is curing some blood cancers outright. The word "cure" is being used in oncology in contexts where it would have been considered irresponsible even twenty years ago.

Heart disease mortality in the U.S. has fallen by more than 60% since the 1960s, even as the population has grown older (American Heart Association). In the 1950s, a heart attack was essentially a coin flip — you lived or you died, and there wasn't much medicine could do about it. Today, stents can open blocked arteries in minutes. Statins lower cholesterol and prevent heart attacks. Beta-blockers and ACE inhibitors manage blood pressure. Emergency response systems get cardiac patients to catheterization labs within the golden hour. Bypass surgery, which didn't exist before 1960, is now routine. We've turned the number-one killer in the developed world from an almost certain death sentence into something people survive routinely and live decades with.

The cumulative effect of all these advances is hard to overstate. Diseases that defined the human experience for millennia — that shaped our religions, our literature, our architecture, our family structures — have been either eliminated, controlled, or dramatically reduced within the span of a few generations. And we're still accelerating. mRNA vaccine technology, developed for COVID-19, is being adapted for cancer, heart disease, autoimmune disorders, and dozens of other conditions. The next fifty years of medical progress may make the last fifty look like a warm-up.