Vaccinations
Biology: AQA GCSE Higher, topic 3.1.12
Vaccination
Vaccination is the main technique for helping the immune system recognise and destroy pathogens. Immunising (making immune) a large proportion of the population will make it very hard for a pathogen to be spread. The process of vaccination is:
Inject a dead pathogen
- A vaccination injects a dead or inactive form of a pathogen into the blood.
Immune system recognition
- White blood cells recognise that the antigens are foreign and produce antibodies against them.
Memory cells
- Some of these white blood cells remain in the blood as memory cells. If the same pathogen invades the body again, the memory cells are able to:
- Produce antibodies faster.
- Produce more antibodies, meaning that the antibody concentration remains in the blood for longer.
Immunity
- Next time the same pathogen infects the vaccinated person, it will be destroyed by the immune system before it can cause illness.
- Vaccinating a large proportion of the community to protect everyone in the community is known as herd immunity.
- Vaccinating the majority of people makes it hard for the pathogen to spread.
Test yourself on Vaccinations
Which of the following are proven characteristics of vaccination?
Vaccination
Why do white blood cells produce antibodies after a person receives a vaccination?
What happens if the same pathogen infects a vaccinated person again?
Why do vaccinated people respond to reinfection faster than people who have never encountered the pathogen before?