A 30-year-old health care worker is evaluated after having a needle stick from a patient with acute hepatitis B Infection. His physical examination is normal, Serologic tests reveal that he is positive for antibody to hepatitis& surface antigen (anti-HBs) and negative for hepatitis B surface antigen (HbsAg), lgM anti-HBc (igM antibodies to the hepatitis B core antigen), and anti-hepatitis C virus. Which of the following best describes the clinical state of this patient?