Vaccine is

Vaccine is

• A. A substance that is used to keep a person from getting a disease
• B. A medicine to cure infections
• C. A protein that stimulates growth
• D. A substance to boost metabolism

Answer: (A)

Vaccines are substances designed to prevent disease by training the immune system to recognize and fight specific pathogens before you encounter them. They introduce harmless parts of a germ or instructions for your cells to make a harmless piece of it, prompting the body to develop memory cells and antibodies. Then, if you’re later exposed to the real pathogen, your immune system can respond quickly and effectively, often preventing illness or reducing its severity. This preventive purpose distinguishes vaccines from cures for existing infections, and they’re not proteins that drive growth or substances meant to boost metabolism.

Vaccines are substances designed to prevent disease by training the immune system to recognize and fight specific pathogens before you encounter them. They introduce harmless parts of a germ or instructions for your cells to make a harmless piece of it, prompting the body to develop memory cells and antibodies. Then, if you’re later exposed to the real pathogen, your immune system can respond quickly and effectively, often preventing illness or reducing its severity. This preventive purpose distinguishes vaccines from cures for existing infections, and they’re not proteins that drive growth or substances meant to boost metabolism.