Nobel Prize in Physiology or Medicine 2020–2024: Five Years of Breakthroughs

10 Junho 2025

• Physiology or Medicine
• Nobel Prize
• Science History

Over the last five years, the Nobel Prize in Physiology or Medicine has recognized discoveries that have revolutionized our understanding of genetics, molecular biology, and medicine. Below is a summary table of the laureates, their countries, and the main themes:

Laureates and Themes

2020: Discovery of Hepatitis C Virus

• Laureates: Harvey J. Alter (USA), Michael Houghton (UK/Canada), Charles M. Rice (USA)
• Theme: Identification of the hepatitis C virus, enabling blood tests and curative therapies for a major cause of chronic hepatitis and liver cancer.

Before these discoveries, millions were infected through contaminated blood transfusions, with no precise diagnosis. The laureates’ work enabled highly sensitive blood tests, eliminating transfusion-related transmission and leading to antivirals that now cure hepatitis C in over 95% of cases. Antiviral: a type of medication used to treat viral infections by inhibiting the development or replication of viruses. Antivirals are distinct from antibiotics, which target bacteria. The global impact is profound, with the World Health Organization targeting hepatitis C elimination as a public health threat. Gene: a segment of DNA that encodes a molecule (usually a protein) with a specific function. Genes are the units of inheritance first hypothesized by Mendel and named by the Danish botanist Wilhelm Johannsen in 1909. Genes make up only a small fraction of a cell’s DNA; most DNA does not code for proteins and is not part of genes. The phrase “one gene, one protein” summarizes the central dogma of biology: genetic information is transferred from DNA to RNA and then to a protein. World Health Organization (WHO): a specialized agency of the United Nations responsible for international public health. Founded in 1948, the WHO coordinates global health responses, sets standards, and provides guidance on health issues, disease prevention, and control.

Harvey J. Alter. Source: Wikipedia

Michael Houghton. Source: Wikipedia

Charles M. Rice. Source: Wikipedia

2021: Receptors for Temperature and Touch

• Laureates: David Julius (USA), Ardem Patapoutian (Lebanon/USA)
• Theme: Discovery of how our bodies sense temperature and mechanical stimuli, through TRP and Piezo receptors.

Julius used capsaicin (the spicy compound in chili peppers) to identify the TRPV1 receptor, responsible for heat sensation. Patapoutian discovered Piezo1 and Piezo2 receptors, essential for touch and pressure. These findings opened new fields in sensory neuroscience, directly impacting the development of painkillers and treatments for chronic pain, and explaining rare genetic diseases related to proprioception. Pain: an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Pain can be acute (short-term) or chronic (long-lasting), and is a major focus of medical research and treatment. Julius and Patapoutian also collaborated and co-published, highlighting the interconnectedness of the scientific community. Receptor: a protein molecule, usually found on the surface of a cell, that receives and responds to chemical signals from outside the cell. Receptors are essential for communication between cells and for the body’s response to hormones, neurotransmitters, and other signaling molecules.

David Julius. Source: Wikipedia

Ardem Patapoutian. Source: Wikipedia

2022: Genomes of Extinct Hominins and Human Evolution

• Laureate: Svante Pääbo (Sweden/Germany)
• Theme: Sequencing the Neanderthal genome and discovering Denisovans, revealing interbreeding with Homo sapiens and transforming our understanding of human evolution.

Pääbo founded paleogenomics, overcoming technical challenges to extract and sequence ancient DNA. His team showed that modern humans inherited genes from Neanderthals and Denisovans, influencing immunity, metabolism, and even responses to diseases like COVID-19. Immune system: the complex network of cells, tissues, and organs that defends the body against infections and diseases. It recognizes and neutralizes pathogens such as bacteria, viruses, and other foreign substances. For example, Neanderthal gene variants affect blood clotting (F5), pain sensitivity (SCN9A), and antiviral immunity (OAS gene cluster), while a Denisovan gene (EPAS1) increases altitude tolerance in Himalayan populations. Pääbo’s work inspired multidisciplinary collaborations, and his son, Hugo Zeberg, also works in the field, showing family continuity in research. Genome: the complete genetic material of an organism. It includes all genes, non-coding DNA sequences (which are not genes), and also the genetic material in organelles such as mitochondria. For example, the 22,000 human genes make up less than 2% of the human genome.

Svante Pääbo. Source: Wikipedia

2023: mRNA Vaccine Technology

• Laureates: Katalin Karikó (Hungary/USA), Drew Weissman (USA)
• Theme: Discoveries enabling the development of mRNA vaccines, crucial in the fight against COVID-19 and opening new avenues for vaccines and therapies.

Karikó and Weissman faced years of skepticism and lack of funding, but their persistence led to the modification of mRNA to avoid inflammatory responses, making clinical use possible. The technology was rapidly applied to COVID-19 vaccines, setting a record for speed and saving millions of lives. Today, mRNA platforms are being tested for cancer, HIV, and autoimmune diseases. Karikó and Weissman collaborated directly, and their stories inspire scientists about the importance of resilience and international collaboration. mRNA (messenger RNA): a type of RNA that carries genetic information from DNA to the cell’s protein-making machinery (ribosomes). mRNA serves as the template for protein synthesis, playing a central role in the expression of genetic information.

Katalin Karikó. Source: Wikipedia

Drew Weissman. Source: Wikipedia

2024: Discovery of microRNA and Gene Regulation

• Laureates: Victor Ambros (USA), Gary Ruvkun (USA)
• Theme: Discovery of microRNAs, small RNA molecules that regulate gene expression, with profound implications for development, disease, and therapeutics.

Ambros and Ruvkun, who worked in parallel and also collaborated, showed that small non-coding RNAs control gene expression in animals and humans. The microRNA field exploded, revealing roles in cancer, heart disease, neurodegeneration, and immunity. The first RNA interference therapy approved for clinical use (patisiran, for hereditary amyloidosis) is a direct result of these discoveries. RNA-based therapies are now in clinical trials, and the discovery changed our view of so-called “junk DNA.” Both laureates have collaborated with other Nobel winners, such as Robert Horvitz. DNA (deoxyribonucleic acid): a complex organic molecule, DNA is a polymer—a chain made up of simpler molecules. It is composed of four types of molecules: adenine, cytosine, guanine, and thymine, which are nucleotides, the monomers (individual parts) that make up the DNA polymer. Each DNA molecule consists of two long strands of nucleotides that coil into a double helix. The order of nucleotides along the DNA strand is not random; it forms a code, called the genetic code, which stores the information needed to produce all the proteins in a cell. In fact, the DNA in each cell contains the information necessary to reproduce the entire organism.

Victor Ambros. Source: Wikipedia

Gary Ruvkun. Source: Wikipedia

What Unites the Themes and Laureates?

• Molecular and Genetic Focus: All prizes highlight advances in molecular biology, genetics, and the mechanisms underlying health and disease.
• Translational Impact: Each discovery has led to new diagnostics, therapies, or fundamental shifts in biomedical science.
• International Collaboration: Many laureates have worked across countries and institutions, reflecting the global nature of modern science.
• Diversity of Backgrounds: Laureates include immigrants and those with multicultural backgrounds (e.g., Karikó from Hungary, Patapoutian from Lebanon).
• Active Scientists: As of June 2025, all laureates are alive and most remain active in research or academia, except Michael Houghton, who retired but is still alive.
• Interrelations: Several laureates have collaborated with each other or with other Nobel winners, showing the importance of scientific networks.

Controversies and Curiosities

• 2020: Debate over the exclusion of other contributors to hepatitis C research, but the main discoverers were recognized.
• 2021: No major controversies; the discoveries were widely accepted and celebrated.
• 2022: Some discussion about the focus on ancient DNA, but Pääbo’s pioneering work was universally acknowledged.
• 2023: The rapid development and deployment of mRNA vaccines during the COVID-19 pandemic sparked public debate, but the scientific achievement was clear. Karikó’s long struggle for recognition before the Nobel was widely discussed.
• 2024: The microRNA field is vast, and some researchers contributed to its development, but Ambros and Ruvkun’s foundational discoveries were decisive.

Implications for the Present and Future

The awarded technologies and discoveries already have a profound impact today:

• Hepatitis C: The disease is close to eradication in several countries thanks to tests and treatments derived from the 2020 discoveries.
• Learn more: WHO - Hepatitis C
• mRNA Vaccines: The mRNA platform is being adapted for vaccines against cancer, HIV, influenza, and autoimmune diseases, with clinical trials underway. The record speed of COVID-19 vaccine development demonstrated the potential of this technology.
• Nature - mRNA vaccines
• microRNA and RNAi: The first RNA interference therapy approved for clinical use was patisiran (Onpattro), for hereditary transthyretin amyloidosis, in 2018. Since then, six RNAi therapies have been FDA-approved, expanding treatment options for genetic and chronic diseases and potentially revolutionizing personalized medicine.
• FDA - RNAi therapies
• Nature Reviews Drug Discovery - RNAi
• Evolutionary Genetics: Genes inherited from Neanderthals, such as F5 (clotting), SCN9A (pain sensitivity), and variants in the OAS cluster (antiviral immunity), affect current human traits. A Denisovan gene, EPAS1, increases altitude tolerance in Tibetans. These findings help explain disease susceptibility and human adaptations.
• Nature - Neanderthal DNA and COVID-19
• Science - Denisovan gene and altitude
• Sensory Neuroscience: New painkillers and treatments for chronic pain and neurological diseases are being developed based on the receptors discovered in 2021.
• Science - Pain research

In the future, these discoveries are expected to continue transforming medicine, making diagnostics more precise, treatments more personalized, and deepening our understanding of life’s fundamental mechanisms. International exchange, multidisciplinary collaboration, and the value of basic science have proven essential for advances that benefit all humanity.

Conclusion

The last five years of Nobel Prizes in Medicine reflect a golden era for molecular biology and genetics, with discoveries that have immediate impact on human health and deepen our understanding of life itself. Scientific research is fundamental to human well-being and societal progress. However, the rise of scientific denialism and misinformation is concerning, as it threatens historic achievements and hinders access to treatments and vaccines. It is therefore essential to value and disseminate quality, evidence-based information, so that the benefits of science reach everyone and society can make informed decisions about health and public policy.