The Nobel Prize in medicine and physiology for the year 2020 was awarded to two American Scientists, Charles M Rice and Harvey J Alter, and a British Scientist Michael Houghton for their work leading to the discovery of the Hepatitis C virus. The coveted award comes with a gold medal and prize money of 10 million Swedish kronor (which is currently more than USD 1,118,000) which come from an endowment left by the Swedish inventor Alfred Nobel.
Hepatitis A & B were the main types of Hepatitis (liver-inflammation) known earlier. During that time, the majority of hepatitis cases which were blood-borne remained mysterious in terms of their causative agent. The work by Charles M Rice, Harvey J Alter, and Michael Houghton had led to the discovery of Hepatitis C virus which resulted in the understanding of the hitherto unexplained types of blood-borne Hepatitis. This subsequently led to the development of relevant blood tests and the relevant medicines for the Hep-C that saved many lives. Hence, the work of Rice, Alter and Houghton was identified as groundbreaking in terms of providing a way to the solution for a category of diseases which has been termed as a plague by Thomas Perlmann, the Secretary-General for the Nobel Assembly and the Nobel Committee for Physiology or Medicine.
There are in total five types of Hepatitis infections. The background of the discovery of Hepatitis C would be discussed here in relation to Hepatitis A & B. There are other types of hepatitis like Hepatitis-D and Hepatitis E. The Hep-D is caused by a Viriod particle (earlier known as delta particle) which sits on the nucleo-capsid of the Hep-B virus. The identification of the Hep- C virus has been crucial as it provided answers for the cases of Hepatitis which were transmitted through blood, yet were not caused by the Hep-B virus.
In the 1940s, it gradually became clear that liver inflammation or hepatitis occurred through two main causative agents. One was the Hepatitis-A virus which is generally spread through polluted waters and the other one is Hepatitis-B spread by the body fluids and/or blood. During the 1960s and the 1970s, the development of tests and treatment methodologies for Hepatitis B led to a gradual decrease in the number of cases of Hepatitis B, but many cases still persisted in the patients with seemingly possible Hep-B infection. Earlier it was guessed that Hepatitis A might be the reason behind the unexplained cases of Hepatitis. With the refinements and improvements in the testing for Hepatitis A, it was found out through further research that the unexplained cases were not due to Hep-A. Harvey J Alter was involved in this part of the story which pointed out that there was a novel virus which the cause for the blood-borne Hepatitis, which was of a non-A, non-B type.
Further research by Alter and others showed that this non-A, non-B type of hepatitis could be transmitted to the Chimpanzees through the blood. Michael Houghton was instrumental in the part which included the identification of the nucleic acid sequences of the virus from the blood obtained from the infected Chimpanzees. This helped in figuring out the genetic sequence of the novel type of virus. Further studies pointed out this non-A,non-B virus was probably leading to an immunogenic response in the bodies of the chronic patients which were producing antibodies. By this time, a clone of this novel non-a, non-B type of virus was derived from a novel RNA virus of the Flavivirus family. At this stage, the virus was given the name of Hepatitis C.
The last confirmatory segment of the discovery remained which was to prove the exclusivity of the virus in causing the unexplained type of bloodborne Hepatitis. Here comes the role of Charles M Rice who was crucial in identifying the features of the genome of the novel non-a, non-B type of Hepatitis. He found out that the end part of the genome of the Hep-C virus was probably crucial for the replication. His studies further found out that mutations in the end-part of the genome affected the replication and helped in proving the exclusivity of the Hep-C virus in causing the unexplained blood-borne hepatitis cases.
Hence, the three had tremendously helped in identifying the main causative agent for a wide number of cases of Hepatitis transferred either through blood or body fluids. Generally, the people who suffer from chronic Hepatitis- C needs to get a liver transplant. The work of the three scientists helped in developing anti-viral therapies that could counter Hepatitis-C cases. New developments like the direct-acting antiviral medicines and Pegylated Interferon & Ribavirin therapy towards treating the Hepatitis C have been possible due to the works of the trio-Rice, Alter, and Houghton that identified with surety the causative pathogen.