Haley Bridgewater, a graduate student at Boise State University in Idaho, is sure she wants to continue studying infectious diseases after she graduates with her Ph.D., but she's finding it difficult to choose a specific topic within that branch of biomedical science. "My problem is that I like them all. The more I look into specific research topics to narrow down my options, the longer my list of potential topics grows," she says.

Haley's early introduction to science wasn't related to the biological sciences at all. She grew up in Los Alamos, New Mexico, where her dad studied nuclear chemistry. Discussions about chemistry, physics, and rockets surrounded her, and she would often stare up at the night sky to catch a glimpse of a meteor shower or the International Space Station passing by. But she was even more curious about what was below her feet: What makes an insect different from a rock? What does the microscopic world look like? She received a microscope one year for her birthday and carried it with her everywhere so she could try to answer these questions.

Global Experiences

Haley took an advanced biology class in high school, where she learned not only about the living world, but also the many exciting scientific careers available, such as becoming a researcher. She moved to Tacoma, Washington, and earned a bachelor's degree from Pacific Lutheran University (PLU), where she majored in biology and global religion.

“I think it’s really an exciting time for science. Some people might think that everything out there to be discovered has already been discovered, but that’s far from the truth. There is still much, much more to discover,” says John Jimah, Ph.D., an assistant professor of molecular biology at Princeton University in Princeton, New Jersey. We talked with him about how he moved internationally to pursue his career, how his current research on cell membranes could help treat malaria, and how science holds space for everyone.

Throughout our immunology miniseries, we introduced the immune system and its many functions and components. Additionally, we highlighted how vaccines train your immune system, how the system can go awry, and how NIGMS-supported researchers are studying immunology and infectious diseases. Put your knowledge about the immune system to the test by taking the quiz below.

The immune system is designed to closely monitor the body for signs of intruders that may cause infection. But what happens if it malfunctions? Overactive and underactive immune systems can both have negative effects on your health.

What do antibodies, mucus, and stomach acid have in common? They’re all parts of the immune system!

The immune system is a trained army of cells, tissues, and organs that work together to block, detect, and eliminate harmful insults to your body. It can protect you from invaders like bacteria, viruses, fungi, and parasites.

Innate and Adaptive

The immune system is often thought of as two separate platoons: the innate immune system and the adaptive immune system. Although these two platoons have different jobs and are made up of soldiers with different specialties, they work together to prevent infections.

Bacteria can cause many common illnesses, including strep throat and ear infections. If you’ve ever gone to the doctor for one of these infections, they likely prescribed an antibiotic—a medicine designed to fight bacteria. Because bacteria can also cause life-threatening infections, antibiotics have saved many lives. However, the widespread use of antibiotics has fueled a growing problem: antibiotic resistance.

Antibiotic-resistant bacteria can survive some or even all antibiotics. Other microorganisms, including fungi, can similarly become resistant to the medicines that are used to treat them. Infections from these microorganisms affect many people and are difficult to treat. According to the Centers for Disease Control and Prevention, in the U.S. alone, resistant bacteria and fungi infect 2.8 million people each year, and more than 35,000 die as a result.

While she was in graduate school, Mandy Muller, Ph.D., became intrigued with viruses that are oncogenic, meaning they can cause cancer. At the time, she was researching human papillomaviruses (HPVs), which can lead to cervical and throat cancer, among other types. Now, as an assistant professor of microbiology at the University of Massachusetts (UMass) Amherst, Dr. Muller studies Kaposi sarcoma-associated herpesvirus (KSHV), which causes the rare AIDS-associated cancer Kaposi sarcoma.

A Continental Change

Dr. Muller has come a long way, both geographically and professionally, since her childhood in France. She was the first person in her family to graduate from high school, where she excelled in science, and went on to attend École Normale Supérieure (ENS) de Lyon, a research-oriented undergraduate institution in Lyon, France. “We spent weeks at a time in laboratory-based classes, working in real labs. That’s when I realized people could do research full-time, which caught my attention,” says Dr. Muller. She double-majored in biology and geology, and soon chose to focus her career on immunology and virology.

Antibiotics are a class of drugs that treat bacterial infections. They may seem common now, but they were discovered less than a century ago. In 1928, Alexander Fleming, a scientist studying bacteria, found that mold from his bread kept bacteria from growing. He determined that “mold juice” was able to kill different types of harmful bacteria, and he and his assistants worked to figure out what natural product in the mold was actually causing the killing. It turned out to be penicillin!

Thanks to Fleming’s discovery, doctors have been successfully treating bacterial infections with penicillin and other newer antibiotics. But in recent years, some infections that were once treatable with antibiotics no longer respond to them. Some of these infections can be treated with multiple rounds of different antibiotic treatments, but others aren’t treatable at all—even leading to death in some cases.

Over the past 2 years, you’ve probably heard a lot about the spread of SARS-CoV-2—the virus that causes COVID-19—and the emergence of variants. The discovery and tracking of these variants is possible thanks to genomic surveillance, a technique that involves sequencing and analyzing the genomes of SARS-CoV-2 virus particles from many COVID-19 patients. Genomic surveillance has not only shed light on how SARS-CoV-2 has evolved and spread, but it has also helped public health officials decide when to introduce measures to help protect people.

In December 2021, the NIGMS-supported SARS-CoV-2 genomic surveillance program at the University of New Mexico Health Science Center (UNM HSC) in Albuquerque detected the first known case of the Omicron variant in the state, which enabled a rapid public health response. The program’s co-leaders, assistant professors Darrell Dinwiddie, Ph.D., and Daryl Domman, Ph.D., were watching on high alert for it to enter New Mexico, and when it did, they were poised to quickly identify it: