How many doses of the Hepatitis B vaccine Engerix-B are required?

The Hepatitis B vaccine, specifically Engerix-B, is designed to provide adequate immunization through a series of three doses. The standard schedule for administering these doses typically involves the first dose being given at a chosen date, with the second dose given one month later, and the third dose given six months after the first dose. This three-dose regimen ensures the development of sufficient immunity to effectively protect individuals from Hepatitis B infection.

The necessity for three doses stems from the need to stimulate the immune system adequately to produce an effective response, as some individuals may require additional exposure to the antigen to develop complete immunity. This multi-dose schedule is a common practice with several vaccines to ensure lasting immunity and relies on the body's ability to respond effectively over time.