Reportage in the Health and Prevention Centre run by the local committee for social hygiene (CDHS) in Lyon, France. Vaccination against Hepatitis A. Havrix is a vaccination that contains an inactivated extract of the hepatitis A virus. It contains no living germ. Once the vaccine has been injected, immunity occurs 15 days later (for 86% of people) and 20 days later (for 100% of people).