Hepatitis B surface antigen (HBsAg)
- Appears during incubation period (1-6 months), 2-7 weeks prior to symptoms.
- Peaks when the patient is most ill.
- Becomes undetectable in 3-6 months.
- Indicates infection – recent or chronic.
Hepatitis B surface antibody (anti-HBs or HBsAb)
- Arises once the acute disease has resolved.
- Sometimes, not detectable unless until weeks or months after HBsAg has disappeared. This gap is called “window” period.
- Indicates, immunity (by vaccination or infection).
Hepatitis B core antibody (anti-HBc or HBcAb)
- Anti-HBc IgM and elevated serum transaminases also appear shortly before the symptom onset.
- Over the next few months, anti-HBc IgM is replaced with an IgG component.
- IgM = Recent (Acute) infection
- IgG = Chronic infection
Hepatitis B e-antigen (HBeAg)
- Shortly after HBsAg appears, HBeAg and HBV DNA can be detected in the serum and are markers of the acute viral replication.
- Predictor of infectivity.
Hepatitis B e-antibody (anti-HBe or HBeAb)
- Anti-HBe appears shortly after HBeAg vanishes and indicates subsiding viral activity.
- Predictor of low infectivity.
| HBsAg | Anti-HBs | Anti-HBc | HBeAg | Anti-HBe | |
| Never infected (susceptible) | – | – | – | – | – |
| Incubation period | + (1st to appear) | – | IgM (shortly before symptom onset) | + | – |
| Prodrome, Acute disease | + | – | IgM | + | +/- |
| Window period | – | – | IgM | +/- | +/- |
| Convalescence (Recovery) | – | + | IgG | – | +/- |
| Chronic active hepatitis B | + | – | IgG | + | – |
| Chronic non-active hepatitis B | + | – | IgG | – | + |
| Immune due to Vaccination | – | + | – | – | – |
| Immune due to Natural infection | – | + | IgG | – | +/- |
| False positive or infection in remote past | – | – | IgG | – | – |