Hepatitis B Safety ConcernsAs early as 1976, one researcher cautioned that since autoimmunity is involved in the pathogenesis of hepatitis B infections, it they might also be provoked by molecularly similar hepatitis B vaccines. Hepatitis B DistributionNote: the hepatitis B virus produces a few key proteins that are either produced by infection or vaccination. In almost all hepatitis B studies, the presence of absence of those antigens and antibodies to them (e.g., the surface protein hepatitis B uses to infect cells) is assumed to determine if someone previously had a hepatitis B infection, was vaccinated, is immune or has a chronic hepatitis B infection, and if it is a high-viral load infection (which is often more severe). A systematic review found that hepatitis B vaccination reduced acute hepatitis B cases from 25% to 15.7% in intravenous drug users, and created a 31.89% reduction in past or resolved hepatitis B infections — highlighting that not all people in this population fully respond to hepatitis B vaccination. Similar trends in new hepatitis B cases were also seen in other at-risk groups:Note: critically however, the decline in new hepatitis cases was not seen in chronic hepatitis B cases (which has essentially remained unchanged from 19761,2 ).