According to Centers for Disease Control, hepatitis C virus is spread by exposure to large quantities of blood, either through the skin or by injection:
Injection drug use (currently the most common means of HCV transmission in the United States)
Receipt of donated blood, blood products, and organs (once a common means of transmission, but now rare in the United States since blood screening became available in 1992)
Needle stick injuries in healthcare settings
Birth to an HCV-infected mother
HCV can also be spread infrequently through
Sex with an HCV-infected person (an inefficient means of transmission)
Sharing personal items contaminated with infectious blood, such as razors or toothbrushes (also inefficient vectors of transmission)
Other healthcare procedures that involve invasive procedures, such as injections (usually recognized in the context of outbreaks)
Sharing drug products via insufflation
Strategies such as the provision of new needles and syringes, and education about safer drug injection procedures, greatly decrease the risk of hepatitis C spreading between injecting drug users.
No vaccine protects against contracting hepatitis C, or helps to treat it. Vaccines are under development and some have shown encouraging results.