The Nobel Prize Winners for Physiology or Medicine 2023

I’m sure everyone remembers the excitement we felt when the COVID-19 vaccine first became available in 2020. It was a landmark discovery that promised to give our lives back after experiencing social isolation for months. In this post, we will highlight the scientists who have recently received the Nobel Prize for their work that led to the expedited development of the vaccine.

The Nobel Prize in Physiology or Medicine for 2023 was jointly awarded to two brilliant scientists, Drs. Katalin Karikó and Drew Weissman. Dr. Karikó is a Hungarian-American biochemist, and Dr. Weissman is an American immunologist (an expert on the body's defense systems against infections). They were the first ones to discover changes in the mRNA molecule that could make it suitable to be used as a vaccine against the SARS-CoV-2 coronavirus.

How do vaccines work? Vaccines are made up of a weakened or dead form of a bacteria or virus. When the body is exposed to these, it riles up an immune response and easily overcomes the weak or dead bugs. When a vaccinated individual is exposed to an actual infection, they are able to fight it with a strong immune response because their immune system has been sensitized to the bug due to the vaccine. Therefore, they either have a mild form of the disease, or they escape it completely.

So, what is mRNA and how do mRNA vaccines work? mRNA or messenger RNA is a close cousin of the DNA molecule. The DNA carries our genetic code, but because the DNA molecule cannot leave the nucleus, it uses mRNA as a “messenger” or a vehicle that carries specific genetic information outside the nucleus, into the cytoplasm, where specific proteins are made based on the information carried on the mRNA. The structure of a given mRNA molecule is thus specific to the DNA molecule for which it acts as a messenger.

Researchers have tried to test mRNA vaccines in animals for a long time, but did not get very far because of the rapid destruction of the mRNA molecule by the body's defense systems, and also because the mRNA molecule caused a strong reaction in the body. However, Drs. Karikó and Weissman worked together at the University of Pennsylvania to discover minor tweaks in the structure of the mRNA, which overcame these issues.

Once inside a cell, the mRNA molecule uses the cell’s machinery to make the protein it codes for. In the case of the COVID-19 vaccine, this protein forms the outer cover of the virus. Recognizing this protein as as foreign molecule, an individual makes antibodies against it. And when an actual infection with the SARS-CoV-2 coronavirus occurs, the body’s defense systems quickly recognize the outer protein, and destroy it, killing the virus in the process. This is essentially how the mRNA vaccine works!

The important discovery by Drs. Karikó and Weissman paved the road for the use of the mRNA molecule for the development of vaccines. Once the COVID-19 pandemic hit, two mRNA-based vaccines against the virus were developed at record speed and were available for use in December 2020.

The COVID-19 vaccine is the only mRNA vaccine currently approved by the U.S. Food and Drug Administration (FDA). However, this may be an approach for protection against other infections as well. Stay tuned!

-Isha Kapoor

Isha is a senior at Mayo High School in Rochester, MN.

Useful Links & References

What are mRNA vaccines and how do they work?: MedlinePlus Genetics

Press release: The Nobel Prize in Physiology or Medicine 2023