2 Types of Immunity

Learning Objectives:• Explain the difference between active and

passive immunity

White blood cells - recapEngulf Antibodies

Break cell wall Antitoxins

AntibodiesAntibodies attach themselves to the markers (antigens) on the bacteria.

Antibodies

The antibodies have to be the right shape to match the antigens.

Antibodies

The antibodies have to be the right shape to match the antigens.

Antibodies

Your body only knows what shape to make the antibodies after you have caught the disease and become ill.

Match the antibody to the microbe

a

b

d

c

1

2

3

4

Definition

Immune: Not being able to catch a particular disease because you have antibodies in your blood to fight it.

Definition

Vaccine: a dead or weakened version of a disease. Your body can make antibodies without becoming infected.

Vaccination

• Use these words to explain how a vaccine works

Inject dead/weakened antibodies

White blood cells microbe vaccine

Fighting diseaseNATURAL IMMUNITY

This is when antibodies are produced by a person when needed or they are passed on by the mother during pregnancy.

ARTIFICIAL IMMUNITY

Can be done in two ways:

1) A vaccine with dead microbes is injected – the body is “tricked” into producing antibodies ready for the real thing. This is called PASSIVE IMMUNISATION

2) The antibodies are injected directly into the body – this is called ACTIVE IMMUNISATION.

Acquired Immunity

Artificially acquired

Naturally acquired

Active

Active

Passive

Passive

•Antigens enter body naturally

•Antibodies & specialised lymphocytes produced

•Antibodies pass from mother to foetus

•Infant does not produce any antibodies of its own

•Antigens are introduced in vaccines

•Antibodies & specialised lymphocytes produced

•Antibodies are introduced in an immune serum

•Body does not produce any antibodies of its own

LLive attenuated ive attenuated (weakened)(weakened)

• Made from live virus • Altered to be less harmful• Oral polio, MMR and BCG, yellow fever

and one form of typhoid vaccine

Whole-agent Whole-agent vaccinevaccine

Inactivated (killed)• Inactivated micro-organism• E.g. Rabies, most influenza vaccines

Contains whole, non-virulent micro-organisms

Different defence mechanisms

Transmission of microbes

Disease defence - what’s the order?

2 Types of Immunity

Learning Objectives:• Explain the difference between active and

passive immunity