What is vaccination? The World Health Org explains

How do vaccines work? Watch this brief 101

Watch this under-3-minute video explaining how vaccines use the body's immune system to prepare our bodies against viral and bacterial threats to our health.

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.

Key milestones in the history of the World Health Organization

The World Health Organization, a UN agency founded in 1948, was first proposed at the 1945 UN Conference to coordinate global health efforts. This interactive timeline marks the WHO’s 75th anniversary with major public health milestones.

What are universal vaccines?

As viruses mutate and develop, vaccines have to adapt, leading to regular recommended injections like flu shots. Researchers are working to develop universal vaccines that aim to protect against multiple virus variants if not entire virus families. These vaccines work by creating broadly neutralizing antibodies (bnAbs) that target aspects of viruses that don't typically mutate and are integral to the virus' survival.

Herd immunity works by slowing down viral transmission until it dies out

Herd immunity refers to a population whose vaccination rates against a given virus are high enough that transmission dies out before the bug can find the next unvaccinated person to infect. Rates needed to achieve this depend on how contagious a virus is. This video gives a quick visual explanation of how it works.

An overview on germ theory, the crucial framework developed by Louis Pasteur

Germ theory of disease is based on the concept that many diseases are caused by infections with microorganisms, typically only visualized under high magnification. Read this general overview to understand the basic framework which allowed for development of vaccines.

Understanding vaccine side effects

A vaccine is a medical intervention, and as with any medical intervention, may have side effects. This article discusses side effects and adverse events related to vaccination.

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.

The American Veterinary Medical Association advocates for vaccinations for pets to extend their lives

The American Animal Hospital Association provides guidelines, while many states legally require certain vaccines, such as rabies. Vaccinating healthy pets—even indoor-only pets—prevents outbreaks and protects other vulnerable animals, and adverse effects, such as allergic reactions and injection-site irritation, are rare. (Some readers may experience a paywall.)

The HPV vaccine reduces cervical cancer rates by 90% or more

Cervical cancer is the fourth most common cancer in women globally. Almost all cases (99%) are linked to infection with high-risk human papillomaviruses. However, cervical cancer is both treatable and preventable—and we may be able to prevent most cases through vaccination.

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.

What are zoonotic diseases?

Interspecies interactions are a breeding ground for disease transmission. This basic background information on zoonotic disease from the Centers for Disease Control and Prevention (CDC) chronicles the different ways humans can get sick, identifies what groups are particularly vulnerable, and offers links to other resources.

The ABCs and FAQs on GMOs from the WHO.

GMOs (or genetically modified organisms) are a subject of great debate in the food world…but how come? GMOs are organisms whose genetic materials have been altered in a way that does not occur naturally in order to create a product that has a...

The WHO’s guidance on 5G, radiation, and health

5G is the latest wireless mobile phone technology, first widely deployed in 2019. 5G is expected to increase performance and a wide range of new applications, including strengthening e-Health (telemedicine, remote surveillance, and telesurgery).

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.

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.

What are the universal human rights?

This video outlines what basic human rights are, who gets to pick them, who enforces them, and how. The basic idea of human rights states that each of us is entitled to the same basic rights and freedoms, no matter who we are or where we are born....

See the evolution of Ebola vaccine and treatment development.

Humans need vitamins, but research is mixed on taking supplements

When an organism needs an organic molecule to survive, but cannot synthesize enough of it itself, that molecule is called a vitamin. Typically, we consume vitamins through food, but many resort to supplements—a common and mostly unregulated practice.

Influenza infects up to a billion people worldwide each year

The World Health Organization estimates that seasonal influenza causes about 1B cases annually, including 3 to 5M severe illnesses and between 290,000 to 650,000 deaths.

Who’s who at the Vatican?

The Vatican is a massive organization whose processes and positions can appear impossibly dense to the common public. But, as this explainer from a University of Dayton professor makes clear, the Catholic Church's bureaucracy functions much like similarly-sized companies and universities. While the processes might still seem unnecessarily complex after reading, you'll at least be able to trace the org chart from the Pope on down.

Roughly 60,000 people serve 11 UN peacekeeping missions

One of the UN’s primary roles is peacekeeping—deploying personnel to conflict zones to maintain stability and protect civilians. The Better World Campaign’s page on UN peacekeeping offers a comprehensive overview of these missions, highlighting their global reach and the involvement of over 2 million personnel from 125 countries across 71 operations.

Everything you need to know about WWI

Summarizing World War I seems like an impossible task, but this article makes a great effort at providing a easily digested survey of the Great War. Read about WWI from the first shots fired by assassin Gavrilo Princip at the Archduke Franz Ferdinand and his wife Sophie, to the various campaigns waged by the war's participants, to the equipment provided to the various fighting forces.

A step-by-step overview of the IVF process

In-vitro fertilization involves a sequence of complex steps to move from egg production to birth. This include stimulating egg production in the ovaries, egg harvesting and fertilization outside the body, embryo culturing and transfer, and methods to support in and increase the likelihood of full-term pregnancy.

The WHO defines burnout as an occupational phenomenon

While it’s not a medical condition, the World Health Organization defines burnout as an occupational phenomenon in the International Classification of Diseases (ICD-11), and considers it separate from general stress.

An overview of the World Wide Web, which is often confused with the internet

When users create a website, they organize content and store it on a web server—one of various types of hardware that make up the internet—in web languages, such as HTML and JavaScript. When visiting the site, a web browser translates these languages into text and other media for consumption.

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

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

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.

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.

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.

Tattoos remain visible on your skin thanks to immune cells called macrophages

Poison ivy's characteristic rash is caused by an allergic response to an oily compound in the plant called urushiol.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

The tragic Pulitzer Prize-winning image 'The Vulture and the Little Girl' (1993) generated controversy, raised concerns about ethics in photography, and eventually led to the photographer's death.

See the 25 of the best photos of auroras from around the world.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in terms of casualties, forces mobilized, and displacement of civilians.

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by more than 1.5 million Muslims each year.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Explore a list of the 100 best novels of all time, compiled by some of the world's best living writers, including Salman Rushdie, Stephen King, and Jennifer Egan.

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.