Vaccine for the win: Nobel 2023
The names of the winners of the Nobel Prize 2023 are out. The prize for physiology/medicine was given on October 2, 2023. Let's learn more about the life-saving contributions of the winners!
Who won the Nobel prize?
The Nobel for 2023 in medicine was awarded jointly to Katalin Karikó and Drew Weissman under the authority of Penn Institute for RNA Innovations, University of Pennsylvania, Philadelphia, PA, USA.
What did they win the prize for?
Both researchers won the prize for their contribution to developing the base of the mRNA vaccine which was used to fight the COVID-19 pandemic against the SARS-CoV-2 virus. Their work had long started before the pandemic and was practically adapted to help the world.
What is mRNA?
mRNA is a messenger ribonucleic acid molecule formed from the DNA (genetic material in most organisms) by the process of transcription. RNA differs from DNA, as it is a single standard, contains ribose sugar and one different nitrogenous base (Uracil in place of Thymine). These mRNA molecules serve as templates to manufacture proteins. RNA can be divided structurally and functionally into messenger, transfer, and ribosomal RNA. For protein synthesis, all three of these are required.
Hence, the process can be summarised as:
DNA → RNA→ proteins
Certain viruses including the coronavirus have RNA as genetic material and infect the host cells. To stop the spread of the viruses scientists came up with mRNA vaccines.
How do mRNA vaccines work?
The mRNA part of the virus is synthesized in the laboratory. Only the non-pathogenic part is used. For example- the RNA used for the coronavirus vaccine expressed the spike protein present on the virus's surface.
These non-pathogenic particles cannot infect the body. These mRNA molecules are injected into the body enveloped by lipid layers which provide safety to these molecules.
These viral mRNA particles enter our cells and are processed by the host machinery. For example - the body produces a spike protein molecule in response to the spike protein mRNA.
These molecules are processed, packaged, and expressed on receptors on the surface of the cells (major histocompatibility complex - l ).
These protein particles are then recognised by cytotoxic T cells, which in turn kill the infected cells.
Another way the immune system works is that B lymphocytes recognise the foreign spike protein particles and produce antibodies against them.
B cells can further interact with T helper cells and produce inflammatory actions.
When the virus actually infects the body, the memory B cells attack the virus with an army of antibodies. T cells and macrophages also participate in the action and do not let the virus take over the host.
mRNA vaccines are considered more efficient than attenuated live virus vaccines and protein virus vaccines because it isn't fatal to immunocompromised individuals and provide better immune response.
What did the recent winners contribute?
The winners Katalin Karikó and Drew Weissman contributed to the working of the mRNA vaccine. While both scientists were experimenting, they noticed that the addition of viral non-immunogenic mRNA caused an exaggerated immune response in the hosts, which rendered the vaccine quite useless. They worked out a way to transfer mRNA into the host cell without producing an exaggerated immune response. They did this by modifying uracil bases to pseudo-uracil bases in the structure of RNA. This little modification which is present in nature (in transfer RNA) enabled them to admit mRNA into the host as a vaccine.
Through their knowledge and understanding of the biochemistry of the vaccines and cellular biology, both scientists laid out the basic principle used to produce mRNA vaccines against a global pandemic saving millions and millions of lives.
References:
https://www.nobelprize.org/prizes/medicine/2023/summary/