. Hepatitis B Virus (HBV) is a highly contagious virus that infects the liver, causing inflammation and potentially leading to chronic liver disease, cirrhosis, or liver cancer.
. It is transmitted through contact with infected blood, sexual contact, sharing needles, from an infected mother to her baby during childbirth, and through contaminated medical equipment or blood transfusions.
. Symptoms of HBV infection include fatigue, jaundice, dark urine, pale stools, abdominal pain, and nausea, although many infections, especially in early stages, are asymptomatic.
. HBsAb is a protein produced by the immune system in response to the HBsAg. it indicates that a person has developed immunity to Hepatitis B, either from a prior infection with recovery, when HBsAg is no longer detectable, or from successful vaccination.
. Clinically, HBsAb is useful in screening to determine whether an individual is immune to HBV or requires vaccination, and it is also used to monitor immunity levels in high-risk populations, such as healthcare workers. Furthermore, it helps differentiate between immunity acquired through vaccination and that acquired through natural infection when interpreted alongside other markers like HBcAb.
. A protective level of HBsAb is typically considered ≥10 mIU/mL, which indicates adequate immunity (WHO).