About immunisation > Science

• What is a vaccine?
• How do vaccines work?
• Active immunity
• Passive immunity
• How are vaccines made?
• Monitoring vaccine safety
• Monitoring vaccine effectiveness
• The life cycle of a vaccination programme
• How immunisation works - animation
• What is herd immunity?
• Herd immunity - animation
• Factors affecting herd immunity - Environmental factors
• Factors affecting herd immunity - Strength of a person's immune system
• Factors affecting herd immunity - How infectious the disease is

Herd immunity - animation

This animation demonstrates how herd immunity is achieved.

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