2.61 understand that vaccination results in the manufacture of memory cells, which enable future antibody production to the pathogen to occur sooner, faster and in greater quantity

Vaccination

In the time it takes your body to make antibodies for an active pathogen it can make you very ill or even kill you. To avoid this you can be vaccinated:

1. An inactive pathogen is injected into the body. These still have the antigens of the pathogen so trigger an immune response.
2. Your lymphocytes produce antibodies to attack them. 
3. Some of these lymphocytes, which are now specific to the pathogen, will now remain in your system forever. These are called memory cells. 
4. If the pathogen is ever recognized again then the antibodies will be released quickly and in great numbers so the immune response is much faster.