Hepatitis C: curable with antivirals but no vaccine
Hepatitis C is a virus spread by blood that direct-acting antivirals (tablets that block proteins the virus needs to copy itself) can cure, yet no licensed vaccine exists.
Remember
Hepatitis C can be cured with direct-acting antivirals, yet no vaccine prevents it, so control depends on screening, treating and reducing exposure to infected blood.
Hepatitis C is caused by an RNA virus that spreads through contact with infected blood, for example when needles are shared. Chronic infection often causes no symptoms for years, yet left untreated it can progress over the years to cirrhosis, which is scarring of the liver, and to liver cancer.
The success story is treatment. Direct-acting antivirals are oral tablets that block proteins the virus needs to copy itself, such as the protease and polymerase enzymes. A daily course lasting 8 to 12 weeks cures more than 95 percent of people, which here means that, at least 12 weeks after treatment, no virus is detected in the blood.
There is no licensed vaccine. The virus has an RNA genome that changes readily, so many slightly different versions of it exist. Its surface proteins are the antigens (the parts of a germ that the immune system recognises), and because they keep changing, antibodies that target one version may not recognise another version. A vaccine would be aiming at a moving target.
Since there is no licensed vaccine, control depends on testing, treating and reducing exposure to infected blood. In contrast, hepatitis A virus and hepatitis B virus can both be prevented by vaccines. Hepatitis B has antiviral treatments that control the infection, but they do not usually cure chronic infection.
Key facts
- Spread
- Hepatitis C is an RNA virus passed on through contact with infected blood, for example through shared needles.
- Treatment
- Direct-acting antivirals taken as tablets for 8 to 12 weeks cure more than 95 percent of people.
- Vaccine
- There is no licensed vaccine, because the RNA genome of the virus changes readily.
- Untreated infection
- Untreated chronic infection can lead to cirrhosis and liver cancer.
- Contrast
- Hepatitis A virus and hepatitis B virus can be prevented by vaccines, and hepatitis B is controlled but not usually cured by antivirals.
- Control
- Public health relies on testing, treating and reducing exposure to infected blood.
Exam traps
- Routine childhood vaccination in the UK does not protect against hepatitis C, because that schedule protects against hepatitis B and no licensed vaccine exists for hepatitis C.
- Antivirals that suppress a virus without usually curing it describe chronic hepatitis B, whereas for hepatitis C direct-acting antivirals can clear the virus.
- Faeco-oral spread (through stool-contaminated food or water) is how hepatitis A virus and hepatitis E virus usually travel, whereas hepatitis C spreads through contact with infected blood.
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