A 1954 outbreak at a Boston boarding school allowed scientists to isolate the measles virus

The measles vaccine has saved an estimated 94 million lives since its introduction

Measles killed an estimated 2.6 million people globally in 1980, after the development of a vaccine but before its widespread dissemination. By 2014, that figure had dropped to an estimated 73,000.

Measles was declared eliminated in the US in 2000

Following a decades-long vaccination campaign, health officials declared victory over measles. This formal definition does not mean limited outbreaks no longer occur, but that ongoing endemic transmission for longer than 12 months has been prevented.

Measles evolved from an ancient cattle disease as early as 3,000 years ago

Genetic analysis suggests that the closest modern relative of measles is a livestock virus known as rinderpest, with the viral strains diverging between 2,000 and 3,000 years ago. The timing coincided with the rise of major cities above 250,000 people, offering a novel transmission route for the newly mutated measles virus.

Measles reached global transmission during the 15th- and 16th-century Columbian exchange

Devastating diseases like smallpox, influenza, measles, and other viruses were largely introduced into the Western Hemisphere beginning with the 1492 arrival of Christopher Columbus and the ensuing age of exploration.

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.

Current US measles outbreak data from the CDC

This data portal from the Centers for Disease Control and Prevention tracks current cases, hospitalizations, and deaths from measles. A 2025 outbreak in Texas and New Mexico drove US cases to their highest levels since the early 1990s.

Measles is one of the most contagious preventable diseases

The virus’s ability to persist in the air for up to two hours means an infected person could enter a room, leave, and two hours later infect someone else entering the room. Its location in the body’s upper respiratory tract also makes it easy for viral particles to be sneezed or coughed into the air.

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.

Measles infection can cause long-term immune system “amnesia”

The measles virus attacks the body's immune system, including preying on T and B cells in the lymphatic system. These cells hold memories of past infections, which can be degraded as the virus destroys them. This leaves patients susceptible to other infections for a year or longer.

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.

HFMD was first reported in 1957 in New Zealand

The first clinical report involved eight kids with the characteristic sores in New Zealand, and then in the years that followed there were dozens more cases there and also reports of outbreaks in England and Scotland, among other settings, including the US.

The CDC’s “Pink Book” chapter on measles

The agency’s “Pink Book” is meant to be a comprehensive guide on various diseases and their treatments. This chapter on measles reviews how it works and common symptoms, and provides information on the MMR and MMRV vaccines.

A technical look at the measles virus and its life cycle

The measles virus is made up of a single strand of RNA, packaged inside an envelope that varies in shape and size. A negative-sense paramyxovirus—the same family as mumps—the virus is encased in proteins that help it attach to immune cells inside the body.

In 1933, the influenza virus was first identified through “ferret flu” experiments

In 1933, British researchers dripped filtered nasal fluids from a sick colleague into ferrets, which quickly developed “ferret flu.” This experiment proved influenza was viral, not bacterial, and established the basis for modern flu vaccines.

Since 1600, the longest stretch without an outbreak that killed 10,000 was four years

We think of pandemics as unlikely events, but disease outbreaks are surprisingly common. Over the past 400 years, the longest stretch without an outbreak that killed at least 10,000 people was just four years. The next pandemic can't be precisely known, so experts and policymakers focus on preparation.

The virus was officially described for the first time in 1789

Michael Underwood, an English physician and surgeon, was the first to describe the disorder, noting it caused disability in the lower extremities in children. Large-scale outbreaks of the disease were not observed until the late 19th century.

The history of germ theory, which explains that illnesses are caused by microorganisms

For centuries, the miasma theory, which held that illnesses were caused by clouds of "bad air" produced by decaying organic matter, was the accepted explanation for the spread of disease. The development of microscopes and the subsequent technology to isolate bacteria and test disease spread in mice greatly contributed to contagionists overturning miasmatists.

The first major norovirus outbreak sickened half an elementary school

In 1968, 50% of an Ohio school got ill from this foodborne pathogen. The disease name is a nod to that original strain discovered in Norwalk, Ohio, when half the elementary school students became ill. Almost all kids reported nausea and vomiting. Everyone recovered.

See the evolution of Ebola vaccine and treatment development.

Why we don't have an answer for the common cold

Since a landmark study of the common cold in 1925, researchers have learned much more about the seasonal ailment. Despite continuous study, people still contract colds for similar periods of time at the same rate with the same symptoms, and there's no vaccine. This article explains how the many viral strains make it hard to control.

Maryland required cholera researchers to fly a yellow warning flag—signifying quarantine dangers in the 1970s

University of Maryland Hospital researchers intentionally infected volunteers with the cholera bacterium in the late 1970s to further their understanding of the disease. They proceeded with this work following the recommendation of a US government panel. (Some users may encounter a paywall.)

The 2026 Ebola outbreak in the DRC is spurring new Ebola vaccine development for the Bundibugyo species

An experimental vaccine candidate from Moderna will use the company's mRNA vaccine platform—the same one which enabled the COVID-19 vaccine to be rapidly developed during the pandemic.

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

The 'Penicillin Girls' made mass production possible

In Oxford during the early 1940s, six female technicians—later dubbed the “Penicillin Girls”—worked long hours tending mold cultures and extracting tiny amounts of penicillin.

Massachusetts passed the first compulsory education law as early as 1642

The legislation required families to instruct children in religious and colonial law. By 1852, Massachusetts mandated that all children ages 8 to 14 attend school. By 1918, every state had a similar law.

Land use changes in Connecticut may have helped to enable Lyme's leap into humans

Forest clearing and fragmentation, alongside suburban development, may have contributed to the emergence of Lyme disease in humans in the 1970s. Those changes brought mice, carriers of the disease, into greater contact with people. Climate change is also facilitating Lyme's spread as tick populations survive milder winters and move northward.

In 1865, Hawaii's king authorized forcible removal, quarantining of those with leprosy

King Kamehameha V authorized the removal of anyone with leprosy symptoms and for them to be placed in a medical facility later maintained by the Catholic Church on Moloka'i, Hawaii's fifth largest island. Patients weren't allowed to transfer to other medical facilities until 1969.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

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

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Poison ivy can cause rashes year-round since all parts of the plant contain urushiol, the oil that triggers our allergic response.

In 2019, a laptop loaded with six of the worst malware in history and described as 'an exhibit of historical weaponry' sold for $1.3M.

Exploring the Larry Bird punch that almost changed March Madness

About 12.5% of US adults experience a phobia in their lifetime, a diagnosis that hinges on the intense fear interfering with daily life and persisting for at least six months.

View the ten deadliest tornadoes in US history.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

See the most iconic photos from four decades of LIFE magazine

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

A small portion of The Winstons' 'Amen, Brother,' an obscure '60s gospel record, is the basis for thousands of hip-hop tracks, making it one of the most sampled records ever that's informally known as 'the Amen break.'