VaccinationSpec 10.1.11, 10.1.12
In short
Vaccination is putting weakened pathogens or their antigens into the body to give active immunity without suffering the disease. The antigens stimulate lymphocytes to produce antibodies, and memory cells are made that give long-term immunity. When a large proportion of the population is vaccinated, the pathogen has fewer susceptible hosts, so the disease spreads less.
Vaccination gives active immunity without the person having to suffer the disease.
- Weakened pathogens or their antigens are put into the body.
- The antigens stimulate an immune response by lymphocytes, which produce antibodies.
- Memory cells are produced that give long-term immunity. If the real pathogen enters later, memory cells respond quickly and make large amounts of antibody.
When a large proportion of the population is vaccinated, the pathogen has fewer susceptible hosts to infect. It is passed on less often, so the disease spreads less, and people who cannot be vaccinated are protected too.
Vaccines contain weakened pathogens or antigens, not antibodies. The person makes the antibodies.
Written and checked against the Cambridge IGCSE Biology (0610) specification · Updated October 2026