Penicillin is prescribed at the highest rate of any antibiotic due to its effectiveness against numerous common pathogens, low price, and long track record.

Experts widely rank penicillin’s discovery among the most important advances in medicine. It launched the antibiotic era, transformed once-deadly infections into treatable illnesses.

When penicillin became widely available in the 1940s, newspapers and doctors alike celebrated it as a “wonder drug” that could cure infections once considered fatal.

Alexander Fleming’s discovery of penicillin revolutionized modern medicine. But the same man who pioneered the development of antibiotics also recognized that bacteria could make sntibiotics obsolete if they were used irresponsibly. This story sheds light on Fleming’s discovery—and on his prophetic warning about antibiotic resistance.

Despite its promise, US production of penicillin remained minimal in 1942—enough to treat fewer than 100 patients nationwide. Within two years, output expanded into millions of doses to supply troops for D-Day.

By 1943, the US War Department made penicillin its second-highest priority—just after the Manhattan Project. Producing enough of the antibiotic for the D-Day invasion became a central mission of Allied science and industry.

Alexander Fleming, Howard Florey, and Ernst Chain received the 1945 Nobel Prize in Physiology or Medicine for discovering and developing penicillin.

In the early 20th century, pneumonia was a top cause of death worldwide, often fatal without effective treatment. Penicillin turned a once deadly infection into one of the most treatable bacterial diseases.

Between 1840 and 1883, scarlet fever was among the leading causes of childhood death in the United States, with case fatality rates ranging from 15% to 30%. Today, thanks to antibiotics like penicillin, the mortality rate is below 1%.

The overuse and misuse of antibiotics are significant contributors to the rise of antibiotic resistant bacteria. Experts say antibiotics should only be used for specific medical problems, and patients need to be sure to take antibiotics exactly as prescribed in order to reduce the risk of antibiotic resistance.

By June 1944, Allied stockpiles included 2.3 million doses of penicillin—enough to ensure that every soldier wounded during the pivotal Normandy landings could receive treatment.

Antibiotics have long been used in agriculture to treat diseases in animals and plants. However, antibiotics are also often misused, to treat non-bacterial diseases, to encourage growth in animals, and more. This expansive use of antibiotics has become one of the primary sources of the emergence of new superbugs.

The vast majority of bacterial treatments were developed during the "Golden Age of Antibiotics," an era of rapid innovation and drug discovery that led to the reduction of millions of deaths worldwide. Since 1970, only eight new antibiotic classes have been discovered.

The COVID-19 pandemic was caused by a virus, and viruses can’t be treated with antibiotics. But recent research finds that COVID patients were given a tremendous amount of antibiotics, contributing to the problem of antibiotic-resistant bacteria. Why? This NPR feature sheds light on an unexpected side effect of the pandemic.

Over decades, bacteria have grown increasingly resistant to antibiotics. This resistance now causes an estimated 1.27 million deaths each year and is associated with nearly 5 million deaths worldwide, according to the World Health Organization.

In 1939, a team at Oxford—including Howard Florey, Ernst Chain, and Norman Heatley—revived Fleming’s forgotten discovery. Using makeshift equipment like bedpans and milk churns, they purified enough penicillin to prove it could treat deadly infections.

Since 1990, antibiotic resistance has claimed at least one million lives annually and is projected to account for 39 million deaths between now and 2050 if current trends continue. The expanded use of antibiotics, particularly in agriculture, combined with a slowing pipeline of new drugs has led to the crisis.

Fleming is credited with the discovery, but since he was not a chemist, he was unable to purify and scale the highly unstable compound's production. This task would fall to Florey and Chain, who crucially developed the antibiotic into its scalable form.

For people with allergies, their immune systems recognize substances as a harmful "other"—cuing an inflammatory response. This podcast explores allergy details and related topics, including how scientists are interested in if the same allergic response mechanisms could underpin other health issues, including severe, painful symptoms around the time of menstrual cycles. Since estrogen acts on white blood cells called mast cells, which leads to the release of histamines—similar to what happens during allergic responses—an understudied question is whether the same process is fueling some of the uncomfortable symptoms around menstruation. An allergist guest notes this raises questions about if antihistamine medications like Pepsid might alleviate them, something that hasn't yet been explored in clinical trials.

The increased use of antibiotics combined with an aging population, is projected to result in an almost 50% increase in global deaths from antimicrobial resistance each year. At the same time, antibiotic use for livestock is expected to increase by 30% over the same time frame.

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.

Why don't we just develop new antibiotics? In part, it's a complex scientific challenge, but market incentives also play a significant role. It can be time consuming, expensive, and most notably, we should use as little as possible to avoid driving further antibiotic resistance.

Market research suggests that the allergies market will continue to grow in the years ahead as the number of allergy diagnoses increases, identifying new patients. Areas of growth include the increasing interest in immunotherapies designed to retrain the immune system through regular exposure to potential allergens via injections and under-the-tongue medical formulations, among other approaches.

The show blends medical history with storytelling and science. In Episode 50, the hosts trace the dramatic origins of antibiotics—from Fleming's moldy petri dish to Florey's wartime labs—and explore their lasting impact on health.

Only about 7% of Amish children in a northern Indiana community have tested positive for common allergens in routine skin prick tests, whereas half of the general US population tests positive for them. Asthma is also extremely uncommon among the Amish, even when compared with other farming communities. Researchers are interested in exploring if approaches like exposing kids across the general population to Amish farm dust might stave off some allergies.

Antimicrobial resistance is a global health threat, driven by the misuse and overuse of antimicrobials in humans, animals, and more. Estimates suggest superbugs could lead to $1T in healthcare costs by 2050, and the world faces a shortage of new drug development to meet the challenge.

What does the rise of antibiotic resistance mean in practical terms? Maryn McKenna is a journalist at the forefront of covering antibiotic resistance since 2007. In this TED talk, McKenna lays out the very real consequences of antibiotic resistance—and what needs to be done to address the problem.

Research published in 2022 suggests that 14.5% of the world's population has contracted Lyme disease. Researchers arrived at that estimate by analyzing the presence of Lyme disease antibodies (indicating prior infection) across 89 studies conducted between January 1984 and December 2021. The works collectively included blood samples from more than 150,000 people.

Antimicrobial resistance is bad news. But there are lots of things you can do to both protect yourself from superbugs and help keep the problem of antimicrobial resistance from getting worse. This page from the CDC offers clear, straightforward guidelines that can help keep you—and your loved ones—healthy.

Research published in 2019 found that almost half of 40,000 surveyed adults with food allergies developed a new food allergy as adults, underscoring that our immune systems may newly misclassify substances later in life.

One reason antibiotic resistance spreads so quickly is that bacteria have multiple mechanisms allowing them to share genetic material. This short video offers a concise explanation for each of these mechanisms, and animation that helps viewers understand how antimicrobial resistance can quickly spread from one organism to another.

Why do certain substances trigger an immune response while others don't? Listen to researchers explain the science in this five-minute video. Food allergies affect around 8% of children and 2% of adults in the US, and—unlike sensitivity or intolerance—they involve the immune system mistaking certain harmless proteins in foods as dangerous invaders, triggering a rapid and sometimes severe defense response.

Skin prick tests and blood tests, the two most common allergy tests, both detect the presence of allergen-specific antibodies. But just because the body has those antibodies doesn’t mean that a person is “allergic” to a substance or that they will develop symptoms of an allergy when encountering the substance. Allergists work with families to interpret the results and sometimes combine that data with approaches including exposure challenges—giving someone a tiny bit of the food or substance they may be allergic to—under medical supervision.

This new medication, called Palforzia, is designed to stave off severe reactions from accidental peanut exposures with a daily dose that is increased over time under an allergist’s supervision. It’s not a treatment that should be administered during an allergic reaction, however. Epinephrine, usually administered via injection, remains the intervention for severe reactions.

Anna Dumitriu's bioart piece was created to commemorate the 75th anniversary of the first use of penicillin in a human patient and intends to raise awareness about the rapid development of antibiotic-resistant pathogens by using bacteria that have essentially been transformed into their pre-antibiotic era state.

In 2024, researchers published an incredibly detailed study aimed at predicting the real-world impact of antimicrobial resistance over the next 25 years. The key findings were clear: the superbug crisis is poised to get much worse and needs to be addressed. This article offers a clear, concise overview of the study, which was published in The Lancet.

Superbugs are a very real problem, but researchers around the world are working to advance our understanding of these pathogens and develop new medicines. This podcast talks with several scientists on the frontier of superbug research, offering insight into what we know—and what the future of medicine may look like.