Vaccine - A biological preparation that improves the immune system’s ability to recognize and destroy harmful infectious agents.⏎
Toxin - A poisonous substance, often a protein, produced by the metabolic processes of living cells or organisms that can cause disease if introduced into the body.⏎
Vector - An organism (usually an arthropod such as a flea, mosquito, or tick) that carries an infectious agent from one host to another.⏎
Sperm Cell - The male gamete, or sex cell, which carries the hereditary material of the male parent and unites with the female egg cell during sexual reproduction.⏎
White Blood Cell - A special type of cell that works as part of the immune system to defend the body against disease and infection.⏎