- HBc (core particle) - indicates replicating HBV
- HBsAg (surface antigen) - the immunogenic component of the vaccine
If pt is negative for HBsAg, anti-HBc, and anti-HBs they are susceptible
If pt is negative for HBsAg, but positive for anti-HBc and anti-HBs, they are immune d/t natural infection (have cleared the infx)
If pt is negative for HBsAg and anti-HBc, but positive for anti-HBs, they're immune d/t HBV vaccine
If pt is positive for HBsAg, anti-HBc, IgM anti-HBc, and negative for anti-HBs, they are acutely infected (can tell b/c IgM goes up first)
If pt is positive for HBsAg and anti-HBc, and negative for IgM anti-HBc and anti-HBs, they are chronically infected
If the HBsAg is negative, the anti-HBc is positive, and the anti-HBs is negative, the interpretation is unclear. Most likely a resolved infection, but could be susceptible, low level chronic infx, or resolving acute infx.