If you have a high enough antibody level to protect you against a particular infection, you are immune.

Active immunity

This is when the body is activated and produces the antibodies needed to fight an infection.

Active immunity is:

  • Slow acting
  • Provides long-lasting protection

The primary response when a microorganism enters the body is described as natural active immunity.

Vaccines provide artificial active immunity.

Passive immunity

This is when ready-made antibodies, from another source, are introduced to the body.

Passive immunity is:

  • Fast acting
  • Only lasts a short period of time

Breastfeeding provides a baby with natural passive immunity.

Anti-venom provides artificial passive immunity after a poisonous bite.