Manufacturing Process

• Genetically engineered cells of common baker's yeast (Saccharomyces cerevisiae) are cultured through several steps so the cells produce hepatitis B surface antigen, or HBsAg. The cultured cells release HBsAg proteins, which are harvested and purified.
  
  

Ingredients

• The final vaccine product contains at least 95% HBsAg protein, while yeast-derived proteins may make up to 5%. The vaccine does not contain a preservative or any substances of human origin. It comes as a suspension that should be shaken before administration.
  
  

Two U.S. Manufacturers

• In the U.S., Merck produces the hepatitis B vaccine Recombivax HB, and GlaxoSmithKline makes Energix-B.
  
  

Formulations

• Each brand of hepatitis B vaccine is available in both pediatric and adult formulations.
  
  

Vaccine Schedule

• The first dose of hepatitis B vaccine is usually given to a newborn baby before hospital discharge, and the next doses are recommended at two and six months of age.