Coloured transmission electron micrographs (TEMs) of hepatitis B (hep B) and hepatitis C (hep C) virions side-by-side. Both viruses are spread primarily from blood-to-blood contact, but can be spread sexually, and both cause infections of the liver. Hepatitis in both forms is typically initially symptomless, but can cause serious chronic liver damage, including cirrhosis and cancer. There is a vaccine for hep B, but no cure. There is a cure for hep C that is 90% effective, but no vaccine.