Hepatitis B vaccine contains:

Options

A. Whole virus
B. Only antigens
C. Antibody
D. Both antigens and antibody

Answer

### Step-by-Step Solution:

1. **Understanding Hepatitis B**: Hepatitis B is a viral infection that affects the liver. It is important to recognize that this disease is caused by a virus known as the Hepatitis B virus (HBV).

2. **Transmission**: Hepatitis B is classified as a sexually transmitted disease (STD), meaning it can be transmitted through sexual contact.

3. **Nature of the Disease**: This infection leads to serious liver complications, and in severe cases, it can be life-threatening.

4. **Prevention**: The good news is that Hepatitis B is preventable through vaccination.

5. **Components of the Vaccine**: The Hepatitis B vaccine contains specific components that help the immune system recognize and fight the virus.

6. **Viral Envelope Proteins**: The vaccine includes viral envelope proteins, which are crucial for the immune response.

7. **Hepatitis B Surface Antigen**: The vaccine also contains the Hepatitis B surface antigen (HBsAg). This is a key component that stimulates the immune system.

8. **Production Method**: The Hepatitis B vaccine is produced using yeast cells, which are genetically engineered to produce the surface antigen.

9. **Immune Response**: When the vaccine is administered, the antigens present in the vaccine trigger the immune system to produce antibodies against the Hepatitis B virus.

10. **Conclusion**: The Hepatitis B vaccine does not contain the live virus itself; it only contains the antigens. Therefore, the correct answer to the question about what the Hepatitis B vaccine contains is that it contains viral envelope proteins and the Hepatitis B surface antigen.

### Final Answer:
The Hepatitis B vaccine contains viral envelope proteins and the Hepatitis B surface antigen.

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