Which of the following is not a first generation vaccines?

Options

A. BCG
B. OPV
C. Cholera vaccine
D. Hepatitis B vaccine

Answer

To determine which of the following vaccines is not a first-generation vaccine, we need to understand what constitutes a first-generation vaccine. First-generation vaccines are typically made from live attenuated pathogens, which are weakened forms of the disease-causing organisms.

Let's analyze the options provided:

1. **BCG (Bacillus Calmette-Guérin) Vaccine**: This vaccine is used to prevent tuberculosis and is indeed a first-generation vaccine. It is made from a live attenuated strain of Mycobacterium bovis.

2. **OPV (Oral Polio Vaccine)**: This vaccine is used to prevent poliomyelitis and is also a first-generation vaccine. It contains live attenuated poliovirus.

3. **Cholera Vaccine**: The cholera vaccine is used to prevent cholera and is considered a first-generation vaccine as it is made from live attenuated or inactivated strains of Vibrio cholerae.

4. **Hepatitis B Vaccine**: This vaccine is used to prevent Hepatitis B and is not a first-generation vaccine. It is a subunit vaccine, which means it is made from pieces of the virus (specifically, the surface antigen) rather than the live pathogen itself.

Based on this analysis, the correct answer to the question "Which of the following is not a first-generation vaccine?" is the **Hepatitis B Vaccine**.

### Summary of Steps:
1. Identify the characteristics of first-generation vaccines (live attenuated pathogens).
2. Analyze each option to determine if it fits the definition of a first-generation vaccine.
3. Conclude that the Hepatitis B Vaccine is not a first-generation vaccine.