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.
The CDC recommends that all children be vaccinated against hepatitis A between their first and second birthdays. People traveling to countries with a high incidence of hepatitis A should be vaccinated, as should persons planning to adopt children from countries where hepatitis A is common. Other people at increased risk for hepatitis A infection include men who have sex with men, people who receive clotting factor concentrates or have chronic liver disease, and illegal drug users.