What are the recombinant DNA vaccines? Give two examples of such vaccines. Discuss their advantages.

Explanation

### Step-by-Step Solution:

**Step 1: Definition of Recombinant DNA Vaccines**
Recombinant DNA vaccines are vaccines produced using recombinant DNA technology. This involves inserting DNA that encodes a specific antigen (a substance that induces an immune response) into a host cell, such as bacteria or mammalian cells.

**Step 2: Mechanism of Action**
Once the DNA encoding the antigen is inserted into the host cells, these cells express the antigen. The expressed antigens are then purified from the cells, and this purified antigen is used to formulate the vaccine.

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