Glossary

Term	Definition
Vaccine	A preparation designed to induce immunity to a specific disease
Venereal	Pertaining to or caused by sexual intercourse or genital contact
Vesicle	Also known as: Blister A small raised area of the outer layer of the skin filled with a watery liquid
Viral load	Number of copies of viral genetic material
Virilization	Development of masculine physical characteristics in a woman
Virus	A microorganism consisting of a nucleic acid (either DNA or RNA) core and a protein coat. A virus requires a host cell to reproduce. It reproduces by infecting a host cell and taking over the nucleic acid of that host cell, making more virus nucleic acid and protein.
Viscosity	Resistance of a fluid (e.g., plasma, serum, cerebrospinal fluid) to flow; thickness or stickiness of a fluid
Vitamin	Any of a group of substances that, in very small amounts, are essential for normal growth, development, and metabolism. They cannot be synthesized in the body (with a few exceptions) and must be supplied by the diet.