Nordic Life Science 1
of these fragments would be derived from the myst
erious virus. Using patient sera (they assumed that antibodies against the virus would be present there) the researchers identified cloned viral DNA fragments encoding viral proteins. Their findings were published in 1989. One positive clone was found, shown to be derived from a novel RNA virus belonging to the Flavivirus family, and this was named hepatitis C virus. The presence of antibodies in chronic hepatitis patients strongly implicated this virus as the missing agent, explains the Nobel Assembly at Karolinska Institutet. he final piece in the puzzle was laid by Charles Rice, studying a previously uncharacterized region at the end of the virus genome that they suspected was important for replication. Using genetic engineering Rice and his colleagues generated an RNA variant of the newfound virus that included the newly defined region of the viral genome and was devoid of the inactivating genetic variations. The RNA was then injected into the liver of chimpanzees, where virus was detected in the blood and pathological changes resembling those seen in humans with the chronic disease were observed – the final proof showing that Hepatitis C virus alone could cause the unexplained cases of transfusion-mediated hepatitis (findings published in 1997). Thanks to the Laureates’ discovery, sensitive blood tests for the virus are now available and antiviral drugs directed at hepatitis C have been developed, greatly improving global health. Niklas Björkström and his colleagues have previously mostly focused their research on understanding why our immune defense is not able to fight the clinical HCV infection. Now that there are new effective treatments available they have shifted their focus, for example towards finding out what determines if a mother-to-child infection will occur in a pregnant HCV positive patient, he says. “We are also interested in investigating how the immune defense is recovering in patients receiving these new medicinal drugs. These are patients who have lived with a chronic infection for decades, which results in the immune defense getting exhausted. It will be important to understand if these now cured individuals could potentially have problems in fighting other infections in the future, for example,” explains Björkström. The Nobel discovery has led to the possibility that the disease can be cured. According to the WHO, antiviral medicines can cure more than 95 percent of persons with hepatitis C infection, thereby reducing the risk of death from cirrhosis and liver cancer. However, access to diagnosis and treatment is low and there is not yet an effective vaccine against hepatitis C. Prevention to a large extend depends on reducing the risk of exposure to the virus, for example in healthcare settings and in higher risk populations. Actions include safe and appropriate use of healthcare injections, provision of comprehensive harm-reduction services to people who inject drugs (including sterile injecting equipment and effective and evidence-based treatment of dependence), testing of donated blood, and training of health personnel. For those infected, it is important to provide education and counseling on options for care and treatment, immunization with the hepatitis A and B vaccines to prevent co-infection from these hepatitis viruses and to protect their liver, early and appropriate medical management (including antiviral therapy), and regular monitoring for early diagnosis of chronic liver disease. The WHO has adopted a strategy with a vision to eliminate viral hepatitis as a public health problem. This is encapsulated in the global targets to reduce new viral hepatitis infections by 90% and reduce deaths due to viral hepatitis by 65% by 2030, by which time 80% of all new cases will receive treatment. The strategy includes raising awareness, promoting partnerships and mobilizing resources, formulating evidencebased policy and data for action, increasing health equities within the hepatitis response, preventing transmission and scaling up screening, care and treatment services. There is currently no effective vaccine against hepatitis C, but research in this area is ongoing, and in our interview with Michael Houghton (p 80), he says he believes we will have a vaccine within the next decade, hopefully sooner. He also thinks that the rapid and mobilized work of developing COVID-19 vaccines might help development in this area too. Niklas Björkström agrees. “A vaccine will most likely be needed if we are to eliminate HCV. It has so far been difficult, but perhaps we could make use of the new lessons learned from the enormous rapid vaccine development that has taken place when it comes to SARS-CoV-2, providing us with new approaches to be used against HCV,” says Niklas Björkström. NLS NORDICLIFESCIENCE.ORG 67