Nobel Prize for Physiology or Medicine 2020 Awarded for Discovery of Hepatitis C Virus

The first Nobel prize this year for Physiology or Medicine was announced yesterday on October 5. This time the Nobel Prize has been awarded to the discovery of a virus which had made a decisive contribution in the fight against blood-borne hepatitis—a major global health problem that causes cirrhosis and liver cancer. The press release of the Nobel committee declared their decision.

The Physiology or Medicine Nobel Prize 2020 is shared by three scientists, namely Harvey J Alter, Michael Houghton and Charles M. Rice. Notably, this year’s Nobel is being conferred upon a discovery made decades earlier.

Hepatitis is the inflammation in the liver and is mainly caused by viruses along with alcohol abuse, toxins found in the environment or some autoimmune responses. Hepatitis through virus has mainly two routes—one through contaminated water or food and the other through blood or body fluid. Majority of the hepatitis virus spreads through water or food and has little long term impact in the body. But, hepatitis virus transmitting through blood or body fluid has significant long term impact like cirrhosis and liver cancer. In addition, the blood-borne hepatitis viruses take a longer time to show its symptoms and in many cases, they become fatal similar to the HIV virus infection.

Much earlier, back in 1940s, the hunt for hepatitis had led to the understanding that the viral agent causing the disease can have either different transmission routes, that is through environmental medium like water or food and through blood or body fluid. In those early days, Hepatitis A virus was discovered that spreads vis water or food, but blood-borne hepatitis virus did take some more time to be found out.

It was only in the 1960s, Baruch Blumberg discovered the blood-borne Hepatitis B virus for the first time and his work was recognised with the Nobel Prize in 1976, two decades after the discovery was made.

But soon it was realised that what Baruch Blumberg discovered was not enough for understanding the hepatitis virus transmitting through blood or body fluid. At that time, Harvey J Alter, one of the recipients of this year’s Physiology Nobel was working at the US National Institute of Health with patients that received blood transfusions.

The Hepatitis B virus was already discovered and could reduce the cases of hepatitis that were transmitted through blood transfusions. But, Alter and his colleagues realised that it was not only Hepatitis B virus, there is some other hepatitis virus that was transmitting in blood transfusion cases. They also searched for Hepatitis A virus, but apart from Hepatitis A and B, they found, there was another virus that was causing blood-borne hepatitis.

Alter and his colleagues found that the unknown hepatitis virus could also infect Chimpanzees when they were transfused with blood from the patients suffering from the blood-borne hepatitis. Alter did an elaborate methodical investigation and concluded a new chronic hepatitis that was caused by some blood-borne virus. This raised concerns about the immediacy of discovering the new virus.

Michael Houghton, the other recipient of the Physiology Nobel 2020 engaged in the hard task of finding genetic sequence of the virus. He and his colleagues made a DNA fragment collection obtained from the nucleic acids found in the blood of infected chimpanzees. He also successfully tried to find the antibodies against the virus in the blood sera of the chronic hepatitis patients. Their research showed that the hitherto unknown virus was an RNA virus and belonged to the family called the Flavivirus. They named it the Hepatitis C virus.

It was remarkable but one question remained puzzling—whether the newly found virus alone could cause Hepatitis. One way to solve the puzzle was to see whether a clone of the virus could replicate and cause the disease. This is where Charles M. Rice, the third recipient of the Physiology Nobel 2020, stepped in. Rice was a researcher at Washington University at that time. His arduous work finally led to the conclusion that Hepatitis C virus alone could cause the chronic hepatitis in patients related to blood transfusion.

It may have taken several decades to get the recognition of a Nobel prize, but the discovery of Hepatitis C virus has had remarkable impact in the fight against viral diseases. Today, blood test with very high sensitivity is available to detect the virus. Also, there are antiviral drugs which target the virus. It is now believed that Hepatitis C could be cured with the help of the antiviral drug.