'Our greatest responsibility is to be good ancestors.'

Jonas Salk developed the first successful polio vaccine—and tested it on himself

The American medical researcher developed the inactivated virus vaccine from 1952 to 1955 and proved that it could prevent disease. He tested the virus on himself and his family in 1954 and then carried out formal clinical trials on more than 1.3 million children.

View this timeline of polio milestones and vaccine development

Polio has a long history in art and medicine, dating back centuries. It includes a representation of an apparent polio survivor with a shriveled leg in ancient Egyptian art. See milestones in the history of polio in this timeline.

Edward Jenner, the father of vaccinations

The British physician was the first to attempt to inoculate someone from smallpox using its milder cousin, cowpox. His innovations and documentations would prove crucial to the deployment of widespread vaccinations.

A quote by scientist Nikola Tesla

"The scientific man does not aim at an immediate result ... His duty is to lay the foundation for those who are to come, and point the way."

A major US-designed polio vaccine was first tested in the Soviet Union

Albert Sabin's live attenuated virus vaccine—requiring two drops in the mouth—didn't garner political support in the US, so it was tested in the Soviet Union in the late 1950s.

Live virus vaccines predated polio—that's how we vaccinate against smallpox

Since 1796, smallpox vaccines have used a live poxvirus related to smallpox. Yellow fever vaccines have used a live weakened form of the virus responsible for yellow fever since 1937.

Improved 19th-century sanitation meant kids encountered polio later, with worse results

Almost all children likely used to contract poliovirus, but scientists suggest that when infants encountered it very early in life—due to poorer conditions and hygiene—they still had some maternal protection from pregnancy or through breastmilk, so the symptoms were more flu-like.

'Few will have the greatness to bend history itself, but each of us can work to change a small portion of events, and in the total of all those acts will be written the history of this generation.'

- Senator Robert F. Kennedy (1925–1968)

How the 1918 pandemic spurred developments in virology and vaccines

This article provides an in-depth historical account of the 1918 Spanish Flu pandemic, including its impact on the global population and how its occurrence spurred significant advancements in the study of viruses—laying the groundwork for the...

Variola: the second-deadliest virus on Earth

Because it was declared eradicated in 1980, many forget smallpox is one of history's deadliest diseases—in its final century, it's estimated to have claimed 500 million lives. This 11-minute video from production studio Kurzgesagt takes a look at...

A history of vaccine rollouts

History tells us the public will tolerate risk of harm from a vaccine if their fear of the disease exceeds their fear of the vaccine.

Most polio cases today are vaccine-derived rather than naturally occuring

Weakened, live virus vaccines—which aren't offered in the US—carry a risk of virus being shed in the stool. Rarely, the shed virus mutates and leads to vaccine-derived polio infections. Most recent polio cases are genetically linked to those vaccines. As shown in this graphic, there are typically hundreds of vaccine-derived polio cases annually.

Wastewater testing has detected genetic evidence of polio, triggering vaccine boosters

Sampling of wastewater in London in 2022 detected fragments of polio virus, suggesting a vaccine-derived version of polio may be circulating. No one became ill, but the finding did trigger calls for a renewed booster inoculation campaign.

60 years after seeing Henrietta Lacks as a patient, her doctor still remembered the unique cervical tumor that gave rise to the 'immortal' cell line now commonly used in biomedical research—it was purple, shiny, and soft—an appearance he said is very different from a typical tumor.

Oral polio vaccines cause approximately 250 to 500 polio cases per year globally

Live, weakened polioviruses in the oral vaccine can very rarely mutate into a disease-causing form and lead to vaccine-associated paralytic poliomyelitis. This oral vaccine is not available in the United States.

'How wonderful it is that nobody need wait a single moment before starting to improve the world.' - Anne Frank

Inactivated polio virus vaccine is the only one offered in the US—it contains no live virus

Inactivated polio virus vaccines cannot cause illness because the virus isn't alive. It's been the only polio inoculation offered in the United States since 2000 and provides almost complete protection

A quote by Whitney Houston

"I believe that children are our future. Teach them well and let them lead the way. Show them all the beauty they possess inside."

A 1954 outbreak at a Boston boarding school allowed scientists to isolate the measles virus and formed the basis for the first measles vaccine.

Henrietta Lacks' tumor cells became the first recognized 'immortal' cell line about 75 years ago, but researchers are still investigating the specific mechanisms that enabled the cells to continuously grow and divide in the laboratory.

Polio commonly spreads when virus-laden feces gets into our mouths

This highly infectious disease is transmitted from one person to another, mainly when we eat virus-laden poop particles. Less frequently, contaminated food or water can transmit the virus, or people can be infected via respiratory droplets (from coughing or sneezing).

'Too often we participate in the globalization of indifference. May we strive instead to live global solidarity.'

- Pope Francis (1936 - 2025)

Read more about the backstory on the 2025 Nobel Prize for immune system work

A trio of scientists won the Nobel in Physiology or Medicine that year, but they performed their award-worthy work beginning about two decades before winning the prize. This announcement includes details about the science and notes that the three scientists will equally share the 11 million Swedish kronor (almost $1.2M).

The COVID-19 pandemic led to a decrease in immunizations in the US and worldwide

Public health funds and resources that were diverted to COVID-19 response reduced efforts to combat polio and vaccinations for polio and other diseases declined during the pandemic, putting more people at risk for polio.

Only one strain of wild poliovirus continues to infect humans

Three strains of polio used to regularly infect humans, but two of the strains were declared eradicated in 2015 and 2019, respectively. In 2019, world health leaders estimated complete polio eradication—if achieved—would save $14B by 2050.

Polish chemist and physicist Marie Curie (1867–1934) on learning

“Nothing in life is to be feared; it is only to be understood. Now is the time to understand more, so that we may fear less."

'To live is to choose. But to choose well, you must know who you are and what you stand for, where you want to go and why you want to get there.'

- Diplomat Kofi Annan (1938-2018)

Robert Koch won the Nobel for his tuberculosis work, but he also pioneered cholera research

Koch was one of the first scientists to isolate the bacterium that causes cholera while investigating an outbreak in Egypt in 1883. He went on to advise about rules to control cholera outbreaks, which formed the basis of the disease control approaches and water hygiene techniques still used today.

Diphtheria was once a leading childhood killer before antibiotics and vaccines

In 18th- and 19th-century outbreaks, some New England families lost as many as eight children to diphtheria, and fatality rates in hospitals often topped 60%. The invention of antitoxins, penicillin, and vaccines dramatically reduced deaths.

Before vaccines, there was 'variolation': what was it?

Before the technology behind vaccinations was discovered, some keen observers of medicine around the globe noticed how previous infections could impact future ones. Learn about the techniques early physicians used before they had vaccines.

The oral, live virus vaccine is the most robust but carries more risks

The live virus vaccine, delivered via oral drops, induces the best protection in the body. Because it includes a live, weakened form of the virus there's an extremely small risk it can sicken recipients and potentially cause paralysis. Recipients also shed the virus in their stool, which can rarely lead to vaccine-derived cases of the virus if the virus mutates. (Some users may experience a paywall.)

Science communicator Bill Nye (1955 - ) on science

"Science is the key to our future, and if you don’t believe in science, then you’re holding everybody back."

Explore the current landscape for patient consent with this 1440 Original video tied to Henrietta Lacks' legacy.

'When I was a boy and I would see scary things in the news, my mother would say to me, 'Look for the helpers. You will always find people who are helping.''

- Mister Rogers (1928-2003)

A quote by Magic Johnson

"Celebrate the life you had, not the life you could've had."

'The bounty of nature is also one of the deep needs of man.'

- Lady Bird Johnson (1912-2007)

'One man can make a difference and every man should try.'

- Jacqueline Kennedy Onassis (1929-1994)

Beyond DNA, Franklin's legacy extends into modern virology and steel production

While remembered for her critical but under-credited role in uncovering parameters for the structure of DNA, Rosalind Franklin made significant contributions across coal chemistry and virus structure. Her research helped improve fuel efficiency, wartime protective equipment, and foundational knowledge in molecular biology.

Polio is currently circulating in only two countries but it remains difficult to eradicate

Wild polio virus is only endemic in two places. Afghanistan and Pakistan are the last two countries with naturally occurring polio cases. Vaccination campaigns have been plagued by misinformation, Taliban bans on vaccines, distrust of public health workers, and violence, including the killing of vaccinators.

'Pioneering is never done in front of cheerleaders urging on a roaring grandstand of popular approval.'

- "Star Trek" actor George Takei (1937-present)

Six of history's most unethical human experiments, from deliberate flu exposure to withholding syphilis treatment

Some of the progress made in mental health treatment, vaccines, blood transfusions, and more came about before the advent of consent and ethics committees, resulting in serious physical and psychological harm that participants in studies were not even anticipating.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

'A life is not important except in the impact it has on other lives.'

- Jackie Robinson, the first Black MLB player (1919-1972)

'One child, one teacher, one book, one pen can change the world'

- Activist and author Malala Yousafzai (1997-present)

A quote by award-winning actor Tom Hanks

"We are still in the position of waking up and having a choice. Do I make the world better today somehow, or do I not bother?"

'You don't get to choose how you're going to die or when. You can only decide how you're going to live. Now.'

- Musician and activist Joan Baez (1941-present)

'We are more fulfilled when we are involved in something bigger than ourselves.'

- Astronaut John Glenn (1921–2016)

Dorothea Lange contracted polio when she was 7, something she said informed her approach to photograph.

Social work pioneer Jane Addams (1860 - 1935) on civilization

"Civilization is a method of living, an attitude of equal respect for all men."

A Quote by Sandra Day O'Connor

"Do the best you can in every task, no matter how unimportant it may seem at the time."