PPIB and hepatitis A virus infection: Therefore, men who are younger than 32 years of age, and especially those between the ages of 18 and 20, are more likely to have been vaccinated against hepatitis B. Men who are now between the ages of 18 and 20 would have likely been required to receive a hepatitis B vaccine in order to enter kindergarten, while men in their mid-twenties may have received a hepatitis B series as an early adolescent.