This year’s Nobel Prize in Physiology or Medicine has been awarded to Katalin Karikó and Drew Weissman for their discoveries that enabled the development of effective messenger ribonucleic acid (mRNA) vaccines against COVID-19.
The prize was selected by the Nobel Assembly of Sweden’s Karolinska Institute medical university and comes with about $1m for the pair to share between them.
The Nobel Prize committee said: “Through their groundbreaking findings, which have fundamentally changed our understanding of how mRNA interacts with our immune system, the laureates contributed to the unprecedented rate of vaccine development during one of the greatest threats to human health in modern times.”
Vaccines train the immune system to create antibodies to help it fight off a particular pathogen, but the method they use to achieve this depends on the underlying vaccine technology.
Traditional vaccines are based on a version or part of the virus, bacteria or other pathogen. It may be live but weakened, such as in the chickenpox or measles vaccines, or dead or inert, such as in the whooping cough or tetanus vaccines.
In contrast, mRNA vaccines do not contain any part of the pathogen but instead contain genetic instructions that direct cells to make a protein, or a piece of a protein, using the body’s natural machinery.
Once injected, the immune system sees the proteins as foreign, so it produces antibodies and T-cells to fight them, training the immune system for potential future attacks.
Despite the mechanism of action for mRNA technology being relatively straightforward, researchers have had to work for years to develop technologies to allow mRNA to work in the real world.
In 2005, Karikó and Weissman jointly developed ‘nucleoside base modifications’, which stop the immune system from launching an inflammatory attack against lab-made mRNA, previously seen as a major obstacle against the use of the technology.
mRNA vaccines, including those from Moderna and Pfizer/BioNTech, have now been used globally to protect against severe COVID-19.
“Through their fundamental discoveries of the importance of base modifications in mRNA, this year’s Nobel laureates critically contributed to this transformative development during one of the biggest health crises of our time,” the committee said.
Beyond COVID-19, the flexibility and speed with which mRNA vaccines can be developed pave the way for new vaccines against other infectious diseases. The approach is also being explored as a way to deliver therapeutic proteins and potentially treat some cancer types.