Some questions to be raised about the hepatitis B vaccine

The author consider some questions to be more carefully studied about the hepatitis B vaccine: route of injection (subcutaneous or intramuscular), amount of antigen (Ag), adjuvant (necessary or not), antigenic and molecular structure of HBsAg. What is important is to get high seroconversion rates, but not to get very high antibody titers (protective immunity is not dependent of antibody titers). Two types of vaccine could be used, and further studied. Why not use in healthy adults and children low dose vaccines (with 1.5-2.5 microg of HBsAg), possibly without adjuvant, and to be injected subcutaneously? And the 20 microg dose of vaccine could be used intramuscularly only for low- or non-responders, in high risk groups.