Nobel Prizes 2020

3 scientists share Prize in Physiology or Medicine: Americans Harvey J Alter and Charles M Rice, and British scientist Michael Houghton have been awarded the Nobel Prize for Medicine or Physiology for the discovery of the hepatitis C virus.

Their Contributions:

• The trio’s work helped explain a major source of blood-borne hepatitis that couldn’t be explained by the hepatitis A and B viruses.
• Their discovery has essentially eliminated post-transfusion hepatitis in many parts of the world.
• Their discovery also allowed the rapid development of antiviral drugs directed at hepatitis C.

Basics:

What is Hepatitis C?

• It is a liver disease. Caused by the hepatitis C virus (HCV): the virus can cause both acute and chronic hepatitis. Hepatitis C is a major cause of liver cancer.

How is it caused and Spread?

• The hepatitis C virus is a bloodborne virus: the most common modes of infection are through exposure to small quantities of blood.
• Treatment: Antiviral medicines can cure more than 95% of persons with hepatitis C infection, thereby reducing the risk of death from cirrhosis and liver cancer, but access to diagnosis and treatment is low.
• There is currently no effective vaccine against hepatitis C; however, research in this area is ongoing.

Types of Hepatitis Viruses:

• There are 5 main hepatitis viruses, referred to as types A, B, C, D and E.
• Hepatitis A and E are typically caused by ingestion of contaminated food or water
• Hepatitis B, C and D usually occur as a result of parenteral contact with infected body fluids. About

Nobel Prize in Medicine:

• Awarded by the Nobel Assembly at Karolinska Institutet, Stockholm, Sweden.
• First awarded in 1901.
• The award comes with a gold medal and prize money of 10 million Swedish kronor (over USD 1,118,000), courtesy of a bequest left 124 years ago by the prize’s creator, Swedish inventor Alfred Nobel

Nobel Prize in Chemistry

• Emmanuelle Charpentier and American Jennifer Doudna share the prize for developing the CRISPR/Cas9 tool to edit the DNA of animals, plants and microorganisms with precision.
• It is possibly the only time in the history of the Nobel Prize that 2 women have been declared the sole winners.

What is CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)? How does it work?

• It locates the specific area in the genetic sequence which is the cause of the problem, cuts it out, and replaces it with a new and correct sequence that no longer causes the problem.

Details (For better understanding- need not mug up):

• An RNA molecule is programmed to locate the particular problematic sequence on the DNA strand, and a special protein called Cas9 (genetic scissor) is used to break and remove the problematic sequence.
• A DNA strand, when broken, has a natural tendency to repair itself. But the auto-repair mechanism can lead to the re-growth of a problematic sequence.
• Scientists intervene during this auto-repair process by supplying the desired sequence of genetic codes, which replaces the original sequence.

Applications

• It's simple: Its simplicity has often been compared to the ‘Cut-Copy-Paste’ mechanism.
• Potential applications: It can potentially eliminate genetic, and other, diseases, multiply agricultural production, correct deformities, and even open up the more contentious possibilities of producing ‘designer babies, and bringing cosmetic perfection.
• For Agriculture: Genes of plants can be edited to make them withstand pests, or improve their tolerance to drought or temperature.