AQA GCSE FOUNDATION Biology: Vaccinations and Immunity

How Vaccines Help Prevent Illness

What are Vaccinations?

Vaccinations are a safe and effective way to protect people from serious diseases. They work by introducing a weakened or inactive form of a virus or bacteria into the body. This "fake" version of the disease triggers the body's immune system to produce antibodies. Antibodies are special proteins that fight off infections.

How Does the Immune System Work?

Your immune system is your body's natural defense against diseases. It recognizes and attacks harmful invaders like bacteria and viruses.

• Antigens: These are molecules on the surface of pathogens (disease-causing organisms) that your immune system recognizes as foreign.
• White Blood Cells: These cells are the key players in your immune system. There are different types, but they all work together to identify and destroy pathogens.
• Antibodies: These proteins are produced by your white blood cells to specifically target and neutralize antigens.

How Vaccines Work with the Immune System

1. Introducing the Antigen: A vaccine contains a weakened or inactive version of the pathogen, which carries the antigen.
2. Triggering the Immune Response: The antigen stimulates the immune system to produce antibodies.
3. Memory Cells: Some of the white blood cells become memory cells. These cells "remember" the antigen and can quickly produce antibodies if the body encounters the real disease in the future.
4. Protection: The memory cells provide long-lasting immunity, meaning your body is protected from getting the disease.

Why are Vaccinations Important?

• Prevent Serious Diseases: Vaccinations have helped to eradicate or greatly reduce the incidence of many deadly diseases, such as smallpox, polio, and measles.
• Protect Vulnerable Individuals: Vaccinations protect not only the vaccinated person but also those around them, especially vulnerable individuals like infants, the elderly, and people with weakened immune systems.
• Herd Immunity: When a large percentage of the population is vaccinated, it becomes difficult for a disease to spread. This is known as herd immunity.

Remember:

Vaccinations are safe and effective. They are one of the most important public health measures in history. They have saved millions of lives and continue to protect people from serious diseases.