Final answer:
The twinrix vaccine is the combined injection for both Hepatitis A and Hepatitis B. It uses capsid protein VP3 for HAV and HBsAg produced through recombinant DNA technology for HBV. This vaccine facilitates convenient immunization against both hepatitis viruses.
Step-by-step explanation:
The vaccine that contains both Hepatitis A and Hepatitis B in a combination injection is known as the twinrix vaccine. This combination vaccine is designed to stimulate the immune system to protect against the Hepatitis A virus (HAV) by using the capsid protein VP3 and against the Hepatitis B virus (HBV) by using the surface antigen, also known as HBsAg, which is produced through recombinant DNA technology. The combination of these antigens in one injection makes it convenient for immunization against both types of hepatitis viruses.
Hepatitis B can be a serious condition that affects the liver, and it can be acquired at birth, making early vaccination important. The Hepatitis B component of the combination vaccine is produced by inserting a synthetic nucleotide sequence for HBsAg into yeast cells (Saccharomyces cerevisiae), where the antigen is then grown, harvested, and purified. This antigen prompts an immune response without the need for the entire live virus. The Hepatitis A component uses the capsid protein VP3 to elicit a similar immune response against HAV. The twinrix vaccine, therefore, provides protection against both Hepatitis A and B, diseases that can lead to serious liver complications.