From new uses for weight-loss drugs to the first CRISPR gene editing therapy, these were some of the most impactful health stories of the year

In world with so much urgent and depressing news, it can be hard to take a moment and reflect on all of the encouraging scientific and medical progress that has happened. But looking back at 2023, there was plenty on the health beat to be awed by.


(Scientific-American, Tanya Lewis) — From the arrival of the first safe and effective vaccines for a common respiratory disease to the first U.S. Food and Drug Administration–approved CRISPR gene editing treatment, these were some of the biggest stories in the health world this year.


A new generation of drugs that result in significant weight loss appeared on the scene a few years ago with dramatic effects. This past year we learned a lot more about other potential benefits of the drugs, which include Novo Nordisk’s Wegovy and Ozempic and Eli Lilly’s Mounjaro. These range from reducing the risk of heart attack or stroke to possibly treating addiction. But the medications come with side effects such as gastrointestinal problems and muscle loss. They’re not cheap, either—they can cost around $1,000 or more out of pocket—and it’s not clear whether insurance will cover them. Still, these drugs are driving significant interest as we continue to learn more about them.


The federal public health emergency put in place to combat the COVID pandemic ended on May 11. The end of the public health emergency marked the conclusion of a set of policies that made it easier and cheaper to access COVID tests, vaccines and treatments, as well as telehealth visits. Consumers must now obtain many of these things with coverage through private insurance, Medicare, or Medicaid or bear the cost themselves. SARS-CoV-2, the virus that causes COVID, continues to circulate and pose a threat to public health. But in May the World Health Organization declared that disease no longer constituted a public health emergency of international concern and said that it was time to transition to long-term management of the COVID pandemic.


There’s an enormous need for organ transplants, but donor organs are in short supply. Improvements in transplant science have made more organs available and usable. Yet too many people still die waiting for one. Now some scientists are exploring another approach: transplanting organs from nonhuman animals. In the past year they have made significant progress in such “xenotransplants.” Following the first transplant of a genetically engineered pig heart into a human in early 2022, this year doctors completed the second such transplant. (Both surgeries were performed on a compassionate use basis because the recipients were terminally ill.) Sadly, the man who received the heart in the latest surgery died after six weeks, likely because his immune system rejected the organ. Other researchers completed successful xenotransplant experiments in people who had suffered brain death, and monkeys that received pig kidneys survived for up to two years. Scientists are hopeful that they can improve the procedures enough to test these techniques in clinical trials in people soon.


Respiratory syncytial virus (RSV) causes annoying coldlike symptoms in most people, yet in very young children or older adults the disease can be deadly. For decades scientists have tried to develop a vaccine to protect against RSV, but a series of disastrous clinical trials in the 1960s ended up making the illness more severe, leading to the deaths of two children. Researchers persisted, however, and as of this year, several safe and effective RSV vaccines were approved by the FDA to protect pregnant people and older adults. The agency also approved an antibody drug that protects children after they’re born.


Nearly a decade after it was first discovered, the gene editing method known as CRISPR is resulting in its first treatments. In December the FDA approved the first CRISPR-based treatment for sickle cell disease. The new therapy is known as exa-cel and made by the biotech companies Vertex Pharmaceuticals and CRISPR Therapeutics. It deactivates a faulty gene for the hemoglobin protein, which transports oxygen around the body. Without the treatment, the gene causes blood cells to develop a sicklelike shape, making them clog up blood vessels. The illness, which disproportionately affects Black people, causes debilitating pain and fatigue. The new treatment, as well as another gene therapy approved at the same time, prevented symptoms of the disease for a year in clinical trials. But longer follow-up is needed to see if there are any side effects, and the cost could make it hard for many people to access.


Even as the immediate danger of COVID has receded somewhat, tens of millions of people continue to be affected by long COVID—a cluster of symptoms such as fatigue, body aches and brain fog that linger long after an infection. The causes of long COVID are still mysterious, yet as Stephani Sutherland wrote in our March issue, it increasingly resembles a neurological disease. Not only does it cause cognitive problems with memory, attention, sleep and mood, but it also has symptoms such as pain and postexertional malaise—extreme fatigue after exercise—that seem to stem from the autonomic nervous system, the autopilot system that controls breathing and digestion, among other things. This new understanding could help guide treatments.


When ChatGPT was released in November 2022, it caused ripples throughout numerous fields—and medicine was no exception. This chat-based artificial intelligence program made by the company OpenAI—along with large language models made by Google and others—is capable of generating text that convincingly mimics human writing. People have already begun to use these programs to diagnose medical conditions, and while the AIs appear surprisingly accurate in some early studies, doctors caution that they are not a substitute for professional medical care. Other people are turning to AI chatbots for therapy. Such apps could help meet the growing demand for mental health services, but as with using them for medical advice, experts urge caution.


Xenotransplants weren’t the only groundbreaking type of transplant to occur this year. In May doctors in New York City completed the first partial face and whole-eye transplant in an Arkansas man who had suffered severe electrical burns while working as a lineman. While corneal transplants are routine, this was the first time an entire human eye was transplanted and remained healthy six months later, according to the transplant team. The recipient, 46-year-old Aaron James, has not regained sight in that eye, but doctors say the eye’s retinal tissue is intact, and there are signs it may be sending signals to the brain. The feat opens the door to restoring the appearance—and possibly, one day, the function—of people who have had traumatic eye injuries.


Put your favorite health and medicine story of 2023 in the comments!