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Active ingredients:


This is one of the hepatitis B vaccines


Active ingredients:

Hepatitis B surface antigen, which is a protein on the surface of the virus.


Engerix-B is a recombinant protein vaccine: the information for how to make specific proteins is inserted into the genome of Saccharomyces cerevisiae, which is yeast. The yeast produce the hepatitis B surface antigen, which is used as the active ingredient in the vaccine. Because these are proteins, not whole bacteria, you cannot get hepatitis B from the vaccine.

Note: yeast is used as part of the manufacturing process, so the vaccine contains traces of yeast. If you are allergic to yeast, please talk to your doctor before receiving this vaccine.

Inactive ingredients:

Adjuvants: strengthen the immune response to the vaccine

Salts: help maintain the stability and pH of the vaccine


Relevant Terms

Relevant Terms

  • Antibody: a protein made by the immune system in response to a foreign particle (antigen). These proteins circulate in the blood and help defend the body against the substance.  

  • Antigen: This is any substance that triggers the immune system to create antibodies. For example, allergens such as pollen are antigens. 

  • Genome: all of the genetic information in a cell.

  • pH: a measure of how acidic or basic a solution is. The scale ranges from 0 (very acidic) to 14 (very basic). A pH of 7 is neutral.


Last updated: Feb. 19, 2023

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