3.1.7 Vaccination

What is vaccination?

Vaccination involves making an individual immune to a disease by introducing a dead or inactivated form of the pathogen, stimulating the immune system to produce antibodies.

How does vaccination protect individuals and populations?

It immunises individuals before they are infected and, when many people are vaccinated, herd immunity reduces the spread of disease in the population.

How does the body respond to vaccination?

White blood cells are stimulated to produce antibodies complementary to the pathogen's antigens. If exposed again, the body can produce antibodies much faster, preventing symptoms.

What do vaccinations replicate?

They replicate the first infection so the immune system responds quickly if the real pathogen enters the body again.

What are two advantages of vaccination?

1. They have eradicated diseases such as smallpox and reduced the occurrence of many others like rubella. 2. They can prevent epidemics through herd immunity.

What are two disadvantages of vaccination?

1. They are not always effective in providing immunity. 2. Some people may experience side effects such as mild reactions (e.g. fever).