Vaccinations
Science: KS3, topic 1.6.39
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.
Test yourself on Vaccinations
Which of the following are proven characteristics of vaccination?
Vaccination
A vaccinated person is infected again by the same pathogen. Why is the pathogen destroyed before it can cause illness?
A person is vaccinated against pathogen X. Later, a different pathogen, Y, infects them for the first time. What is most likely to happen?