Born in Poros Island, Greece in 1941. He received his M.D. degree from the Athens Medical School in 1966 and had a 5-year training in Internal Medicine at University Hospitals of USA (University of Tennessee, University of Illinois and at the New England Medical Center, Boston). In 1975, he joined the Athens University School of Medicine as an Instructor of Clinical Medicine at the Academic Department of Medicine, Hippokration General Hospital, where he worked till his retirement as a Head of the Academic Department of Medicine in the same hospital. In August 2008 he retired with the title of Professor Emeritus and maintaining close scientific and educational activities at the Athens Medical School till the present time. Professor Manesis was a recipient of a Welcome Trust Foundation Scholarship for 1978-1980 and studied the dynamics of liposome-incorporated HBsAg and its adjuvant properties at the Clinical Research Center, London, U.K., in the context of development of a more efficient HBV vaccine. His research interest has been centered in Hepatology and especially in HBeAg-negative chronic hepatitis B, hepatocellular carcinoma, complications of cirrhosis. He has revived the international clinical interest on the value of quantitative measurements of serum HBsAg in the follow-up of interferon- or nucleos(t)ide-treated patients with hepatitis B viral infection. He has published more than 80 original scientific papers in peer-reviewed Gastroenterology and Hepatology journals and he is internationally acknowledged for his contribution in the field of chronic hepatitis B.