Glossary

Adjuvant: In vaccines, a substance that is added to increase stimulation of the immune response


Antibiotic: A medicine that contains chemicals that can slow or stop the growth of a microorganism


Antibody: A protein molecule that is produced by B cells in the body in response to contact with a foreign substance termed an antigen. Antibodies neutralize antigens and are an important part of the immune response against infection. Antibodies are also called immunoglobulins.

Antigen: A substance that can produce a specific immune response


Attenuated: Weakened; in vaccines, the weakening of a virus or bacteria to disable its ability to cause disease


Autism: A disorder characterized by preoccupation with inner thoughts and the self to the exclusion of everything else


Booster shot: A dose of a vaccine that helps the body maintain immunity against a disease


Capsule: An anatomical structure surrounding the body of a bacteria


DNA: Deoxyribonucleic acid, the genetic base of every living organism


DTaP: Combined vaccine that protects an individual from infection with diphtheria, tetanus, and pertussis, typically given as a series during childhood


FDA: Abbreviation of Food and Drug Administration, the government entity responsible for reviewing drugs and vaccines for effectiveness and safety


Flu: Popular name for influenza, an acute viral infection


Hib: Abbreviation of Haemophilus influenzae type b, an acute infection that can cause bacterial meningitis in children


Humoral immunity: Immunity referring to elements dissolved in the blood or body fluids, such as antibodies in the blood, rather than cells


Lymph node: A small mesh of tissue that filters, attacks, and destroys harmful microbes. Part of a network of nodes scattered throughout the body to fight infection


Lymphocyte: B cells or T cells that help the immune system fight an infection and provide humoral (B cell) or cellular (T cell) immunity


Macrophage: A large white blood cell that kills invading microbes and takes the antigens of those cells to helper T cells, so that they can identify and kill the infection


Measles: A highly infectious childhood disease that causes fever, cough, runny nose, and rash on the face and body. Serious complications are rare, but may include pneumonia or ear infections.


Membrane: A thin layer of tissue that covers a surface or divides a space within an organism


Memory cell: T and B cells that control the ability of the immune system to remember a certain invader and prevent it from being able to cause infection in the future


MMR: Combination vaccine that protects an individual from infection with measles, mumps, and rubella (German measles)


Mutate: To change in form, quality, or other characteristic


Nonspecific immune system: A network of specialized cells, such as macrophages, that responds to infections at the same rate, whether it's a first invasion or a subsequent invasion


Pertussis: An acute, highly contagious infection of the respiratory tract that affects individuals of all ages. Also called whooping cough.


Plasma cell: B cells that produce antibodies in response to antigens presented by a macrophage


Polio: Abbreviation for poliomyelitis, an acute viral disease that can result in paralysis, muscle atrophy, and permanent deformity of the limbs


Polysaccharide: A carbohydrate, or sugar, molecule found in the capsules of bacteria in order to enable the bacteria to stay hidden from the immune system


Protective immunity: Describes immunity at a high enough level to protect an individual from infection. Protective immunity can be attained as a result of a vaccine, or as a result of acquiring a particular disease.


Protein shell: Protective coating of protein molecules covering the body of a virus


Specific immune system: Network of cells consisting of B and T cells and antigen-presenting cells that takes several days or more to respond to an infection the first time, but which responds more quickly and powerfully the next time


Stabilizer: A chemical additive that helps a vaccine stay potent during shipping and storage


Sterile: Free from living organisms or contaminants


Toxin: A poison


Varicella: Medical term for chickenpox, a highly contagious disease usually acquired by children, that causes skin rash and itchy blisters on the body

References:

1. National Institute of Allergy and Infectious Diseases. Understanding VACCINES: What They Are-How They Work. U.S. Department of Health and Human Services, National Institutes of Health. NIH Publication No. 03-4219; July 2003. Available at: http://www.niaid.nih.gov/publications/vaccine/pdf/undvacc.pdf.

2. Baggish J. How Your Immune System Works. Emeryville, Calif: Ziff-Davis Press; 1994.

3. Humiston SG, Good C. Vaccinating Your Child: Questions & Answers for the Concerned Parent. Atlanta, Ga: Peachtree Publishers Ltd; 2003.

4. Crowcroft NS. What is so good about new conjugate vaccines? Pharm J. 1999;263:703-704.

5. Centers for Disease Control and Prevention (CDC). Epidemiology and Prevention of Vaccine-Preventable Diseases: The Pink Book. 8th ed. Atlanta, Ga: US Department of Health and Human Services, Public Health Foundation; 2004:9-25.

6. CDC. Parents Guide to Childhood Immunization. Who to contact if your child has a vaccine-related side effect. Available at: http://www.cdc.gov/nip/publications/Parents-Guide/default.htm. Accessed April 27, 2005.

7. Stratton K, Gable A, McCormick MC, eds. Immunization Safety Review Committee, Board on Health Promotion and Disease Prevention, Institute of Medicine. Immunization Safety Review: Thimerosal-Containing Vaccines and Neurodevelopmental Disorders. Washington, DC: National Academy Press; 2001:1-17.

8. CDC. FAQs (frequently asked questions) about MMR vaccine & autism. Available at: http://www.cdc.gov/nip/vacsafe/concerns/autism/autism-mmr.htm. Accessed April 27, 2005.

9. CDC. Vaccines and autism: important conclusions from the Institute of Medicine. Available at: http://www.cdc.gov/nip/vacsafe/concerns/autism/vacc-autism-iom_hcp.pdf. Accessed April 27, 2005.

10. Institute of Medicine. Immunization Safety Review. Vaccines and autism. The National Academies Press Web site. Available at: http://www.nap.edu/books/030909237X/html/ . Accessed May 23, 2005.