Stages of infection

There are four stages of hepatitis B infection:

  • Immune tolerance: the hepatitis B virus replicates freely and there are no symptoms of hepatitis. This phase lasts for several weeks when adults become infected and for decades when infants are infected.
  • Immune response: the immune system mounts an attack on hepatitis B virus-infected liver cells and starts to clear the virus. This stage may last for as little as three weeks when adults are infected or it may persist for ten or more years in people with chronic infection. Symptoms of hepatitis may occur during this stage. A prolonged period of immune response is associated with a greater risk of cirrhosis or liver cancer.
  • Full viral clearance: the immune system has won the battle and active viral replication stops. This is sometimes referred to as seroconversion because the body begins to produce antibodies to the hepatitis B e antigen.
  • Immunity: there is a full antibody response to hepatitis B virus antigen and its genetic material usually disappears. A person with full immunity will not become infected with the hepatitis B virus in the future.
This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.