We have studied a series of 43 patients – who were suffering from uremia, subject to hemodialysis treatment, resulting seronegative to the test for HBV and who had never been vaccinated before – considering the HBS antibody as seroconversion index. We subdivided our patients into three groups, according to the treatment employed. First group: French vaccine; 2nd group: French vaccine + thymopenthine; 3rd group: recombining DNA vaccine + thymopentine. From a statistical point of view, in the 3rd group we obtained a significant seroconversion in terms of patients, if compared with the other gro