A medical student has been immunized with hepatitis B virus (HBV) recombinant vaccine

A medical student has been immunized with hepatitis B virus (HBV) recombinant vaccine. The curve in below figure represents the production of protective antibodies to the viral component present in the recombinant vaccine. Which of the following is the known viral component of the HBV vaccine?

  1. nucleocapsid proteins of HBV

  2. RNA genome of HBV

  3. viral core antigen (HBcAg)

  4. viral e antigen (HBeAg)

  5. viral surface antigen (HBsAg)

View Explanation

The envelope of hepatitis B virus contains an antigen known as HBsAg (hepatitis B surface antigen). This antigen is of importance because production of antibodies to HBsAg indicates immunity against hepatitis B virus, which resulted either from infection or vaccination with HBsAg. Treatment of HBV with a nonionicdetergent removes the envelope and produces the viral core, which contains the hepatitis B core antigen (HBcAg). Antibodies to HBcAg are not protective (choice C). Treatment of the viral core with strong detergents results in the release of a soluble core antigen called hepatitis virus antigen e (HBeAg). Production of antibody to HBeAg signals active disease during which the patient is infectious (choice D). The DNA genome (choice B), or the nucleocapsid proteins of HBV (choice A) are not protective.