After receiving the hepatitis B (HBV) vaccine, a patient's immune system will produce antibodies against the hepatitis B surface antigen (HBsAg), which is the surface protein of the hepatitis B virus (HBV) that is primarily responsible for the virus's infections. These antibodies can be detected through a blood test known as a hepatitis B serology test.
On the other hand, someone who has recovered from an acute HBV infection will also produce antibodies against HBsAg, but in addition, they will also have antibodies against the hepatitis B core antigen (HBcAg) and the hepatitis B e antigen (HBeAg) as part of their immune response to the infection.
Therefore, a difference in serology between a patient who has received the HBV vaccine and someone who has recovered from the virus can be seen in the presence of additional antibodies beyond just HBsAg. Specifically, someone who has had an acute HBV infection will have HBsAg antibodies in addition to HBcAg and HBeAg antibodies, which can be detected through the hepatitis B serology test.