What Are Vaccinations?

Vaccinations protect against diseases by training the immune system to fight infections before they happen.

💡 Key Concept: A vaccine contains a weakened or dead version of a pathogen to stimulate an immune response.

How Do Vaccines Work?

1️⃣ A dead or weakened pathogen is injected into the body.
2️⃣ White blood cells detect the antigens on the pathogen’s surface.
3️⃣ The body produces antibodies to fight the pathogen.
4️⃣ If the real pathogen enters later, the immune system remembers it and produces antibodies quickly, preventing illness.

💡 Key Fact: This gives long-term immunity without the person suffering from the disease.

Why Are Vaccines Important?

✔ Prevents outbreaks of disease.
✔ Reduces transmission between people.
✔ Protects those who cannot be vaccinated (herd immunity).
✔ Eliminates diseases (e.g., smallpox was eradicated due to vaccines).

💡 Example: The MMR vaccine protects against Measles, Mumps, and Rubella.

What Is Herd Immunity?

If enough people are vaccinated, diseases cannot spread easily. This is called herd immunity and protects:
✔ Babies too young to be vaccinated.
✔ People with weak immune systems.
✔ Those who cannot have vaccines due to medical conditions.

Pros and Cons of Vaccination

💡 Example: Polio, Smallpox, and Measles cases dropped dramatically due to vaccination.