Frequently Blood Bank donors are found to have a presence of Total Anti-Bc in the serum in the absence of the Hepatitis B surface antigen (HBsAg) and the Hepatitis B Surface Antigen (Anti-Bs) antibody. This study was designed to determine the serological response to the vaccination against the Hepatitis B virus, and evaluate the effectiveness of the vaccine in such cases, taking into consideration that the protective antibody titers for Hepatitis B are measured in levels above 10 mUl/ml.Thirty-one patients with the HBsAg negative/Anti-Bs negative/Antil-Bc positive serological patterns received three doses of the recombinant DNA vaccine (Hepavax Gene 20 microg), in a 0, 1, 2 months vaccination schedule. Anti-HBs levels were taken 30 days after the application of the last dose. After the 3 doses of the vaccine, the Anti-HBs levels were > 100 mUl/ml in 89% of the cases, > 500 in 50% and > 1000 in 14.3% of the vaccinated patients. Only 3 patients (9.7%) did not show serological response 30 days after the application of the last dose of the vaccine.In conclusion, 90% of the patients administered the HBsAg negative/Anti-HBs negative/Anti-HBc positive serological patterns, obtained Anti-HBs levels considered protectors ( > 10 mUl/m).