Vaccine

Definition

A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease. It typically contains an agent resembling a disease-causing microorganism, which stimulates the body's immune system to recognize and combat the pathogen.

5 Must Know Facts For Your Next Test

1. Vaccines can be made from inactivated (killed) or attenuated (weakened) forms of the pathogen.
2. The primary goal of a vaccine is to train the immune system to recognize and fight off specific pathogens without causing disease.
3. Vaccination leads to the production of memory cells, which provide long-term immunity.
4. Herd immunity occurs when a significant portion of the population is vaccinated, reducing the spread of the disease.
5. Some vaccines require booster shots to maintain immunity over time.

Review Questions

• What are the two main types of agents used in vaccines?
• How do vaccines contribute to herd immunity?
• Why are booster shots sometimes necessary?

Related terms

Pathogen: A microorganism that causes disease.

Antibody: A protein produced by the immune system that recognizes and neutralizes pathogens.

Immune System: The body's defense system against infectious organisms and other invaders.