How long does a hepatitis A vaccination last?

Experts expect the hepatitis A vaccine to confer immunity to the recipient for 20 to 30 years and possibly for life, according to WebMD. A single dose of the vaccine provides immunity within one month of administration.

For full protection from hepatitis A, a person must receive two injections of the hepatitis A vaccine, with the second being received six months after the first, explains Vaccines.gov. A combination hepatitis A and B vaccine, given in the form of three injections, is available for anyone over the age of 18. Patients can get a series of three injections over the course of six months, or they can have three injections during the course of one month and have a booster 12 months later.