The efficacy of a vaccine is not always 100% and it may fail to induce immunity in certain individuals.If individuals develop the disease immediately after vaccination their levels of immunity may not be high enough to prevent the disease and to prevent them passing on the disease to others.Some pathogens, especially respiratory viruses such as Influenza viruses show antigenic variability. They mutate frequently so the antigens are suddenly no longer recognised by the immune system. This means immunity to the disease is short lived.There are many varieties of the common cold virus and Influenza virus that it is not possible to vaccinate an individual against all strains of the virus.Vaccines cannot be produced for some pathogens. Vibrio cholerae bacteria that causes cholera hides in the gut and HIV virus hides inside T-helper cells and macrophages.People may have objections to vaccines for health, religious or medical reasons or concerns over the efficacy or safety of the vaccine.
Vaccination Programme Failure
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Specification: AQA Biology (7401), AS-level, 3.2.4 Cell recognition and the immune system. Topic: Cell Recognition and the Immune System.
Key terms in this lesson
- pathogen
- A microorganism, such as a virus, bacterium, fungus or protoctist, that causes disease.
- antigen
- A protein or glycoprotein, usually on a cell surface, that is recognised as foreign by the immune system and triggers an immune response.
- T-lymphocyte
- A type of white blood cell, matured in the thymus gland, responsible for the cell-mediated immune response.
More in Cell Recognition and the Immune System
- Producing Monoclonal Antibodies
- Active, Passive, Natural and Artificial Immunity
- Vaccination
- Herd Immunity
- Ethics
- MMR Vaccine Case Study
- Structure of HIV Virus
- Replication of HIV Virus
All 30 lessons in Cell Recognition and the Immune System · All AQA AS-level Biology topics