Vaccine

In the syllabus and the exam

Vaccine is examined as the practical, artificial trigger for active immunity, and candidates must be able to explain the full mechanism rather than only stating that a vaccine protects against disease. A complete answer states that a vaccine introduces a weakened, inactivated, or partial form of a pathogen's antigen into the body, this stimulates white blood cells to produce antibodies and, crucially, memory cells, and if the real pathogen is encountered later, memory cells trigger a fast secondary immune response before the person becomes seriously ill. Exam questions sometimes ask why a booster dose is given, and candidates should explain this in terms of reinforcing antibody levels or memory cell numbers where the first response was insufficient, rather than describing it vaguely. This term must always be discussed within the analysis of how the immune system responds, and candidates should describe outcomes and mechanisms rather than making unqualified claims about how effective any vaccine is for an individual.

Example

A measles vaccine contains a weakened form of the virus that trains the immune system without causing the actual disease.

Related terms

AntibodyImmunityAntigen

Source:SRC-DSKP-EN