Vaccine - A biological preparation that improves the immune system’s ability to recognize and destroy harmful infectious agents.⏎
Yeast - A broad group of microscopic fungi that includes harmless forms of yeast used in baking and alcoholic fermentation as well as pathogenic species that can cause disease. ⏎
White Blood Cell - A special type of cell that works as part of the immune system to defend the body against disease and infection.⏎
Species - One of the most basic units of biological classification, ranking just below the genus and comprising individuals or populations capable of interbreeding.⏎
Strain - A genetic variant or specific subtype of a microorganism, such as a virus or bacteria.⏎