Defence mechanisms (CCEA)Active immunity - vaccinations

The body has adapted defence mechanisms to protect itself against the entry of microorganisms.

Part ofCombined ScienceHealth, diseases and micro-organism

Active immunity - vaccinations

A vaccination is the injection of dead or modified .

A man getting an injection

The body’s produce in response to the present in the .

Memory lymphocytes will also be produced – this is the primary response.

If this microorganism is encountered after the vaccine, the memory lymphocytes will produce large numbers of the antibody very quickly.

The individual does not get sick – this is the secondary response.

Sometimes a booster vaccination is needed to maintain the high levels of antibodies needed to provide immunity.