Vaccines and Immunity Grade 9

How do vaccines work?

Vaccines contain dead, weakened, or partial forms of pathogens.

**remember, pathogens are invaders that don't belong in our bodies!

What's in a vaccine?

Dr. Edward Jenner created the world's first successful vaccine. He found out that people infected with cowpox were immune to smallpox. In May 1796, English physician Edward Jenner expands on this discovery and inoculates (essentially, vaccinates) 8-year-old James Phipps with matter collected from a cowpox sore on the hand of a milkmaid. James then developed immunity to cowpox and smallpox from this!

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The first vaccine

But how does this work??

Recall how the immune system works.

​*Remember, antigens are how our bodies identify cells!

​Helper T-Cells are special cells in our immune system that can assist in communication with other cells.

1. The immune system recognizes the pathogen

2. Immune system builds up a defense against the pathogen by creating antibodies (this can take several days to do) and increasing the number of white blood cells.

3. Immune system destroys the pathogen.

4. Memory Cells are created that "remember" how to attack the pathogen if exposed again in the future!

​In Summary...

The weakened, dead or partial pathogens present in a vaccine aren't able to cause disease.

BUT they do trigger an immune response - this is why you may feel some symptoms associated with sickness when you get a vaccine (sore arm, mild fever, etc.).

This is all part of your immune system working to develop a defense and MEMORY CELLS to protect you from the pathogen if exposed to it in the future.

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Vaccines activate the immune system!

Multiple Choice

True/False

Antibodies are specific to germs. Example, the antibody for chicken pox does not work against measles.

• True

• False

Multiple Choice

True/False

Vaccines help your body by causing your body to create antibodies.

• True

• False

Multiple Choice

What are antibodies?

• A specific weapon your body makes and uses to fight germs

• Something your doctor orders for you when you're sick

How do vaccines work?

• vaccines use the body's own immune system to protect it from disease

• a vaccine contains a bit of the pathogen, or a pathogen that has been killed, weakened, or otherwise inactivated

• your immune system doesn't know the bits in the vaccine can't hurt you - just that it doesn't belong!

• your immune system attacks! in the process, it learns how to fight off the real thing.

Herd Immunity

Reducing the spread of infection

What is herd immunity?

• The goal of a vaccination program is to produce herd immunity in the population

• When enough people have been successfully vaccinated, this reduces the spread of infection, even to unvaccinated people, since vaccinated individuals will not spread the pathogen as easily

Why is herd immunity important?

• The more vaccinated people there are, the less people there are as potential carriers of the pathogen

• Some people cannot be vaccinated (people with immune diseases, taking medication that suppresses immune system, the elderly and newborn babies) so these people rely on herd immunity to prevent the spread of the virus to them.

Case study - whooping cough

• If you've known someone with a newborn, they may have asked you to get a whooping cough vaccine before meeting the baby.

• Some immune memories don't last forever - this is true for whooping cough. You need a booster every 10 years to maintain immunity to whooping cough.

• Herd immunity can be lost if people don't maintain their schedule of booster shots - this is concerning as some diseases are able to be 'eliminated', but only if people keep getting vaccinated.

Open Ended

Explain why herd immunity is important for the population as a whole.

Multiple Choice

What is the ability to resist the pathogens that cause a particular disease?

• defense

• immunity

• immune system

Multiple Choice

How are vaccinations able to help us develop immunity?

• Exposure to disease creates antibodies which make us immune

• Exposure to antibodies which makes us the disease immune to us

• Exposure to immunity's which make us antibodies to the disease

Multiple Choice

This allows us to develop an artificial immunity to a disease without ever getting sick from the disease.

• antibiotics

• vaccines

• blood transfusions

Multiple Choice

Why do doctors suggest that people get a flu vaccine each year?

• Viruses replicate more rapidly over time.

• Viruses can mutate from year to year.

• Vaccines are absorbed by the body after a year.

• Vaccines get stronger over time.

Multiple Choice

Which type of microbe can be treated with antibiotics?

• Bacteria

• Viruses

• Fungi

• Protists

Multiple Choice

What is the definition for "a pathogen"?

• an organism that is not transmissible

• bacteria that causes disease

• an organism that causes disease

• virus

Part 2 - Lines of Defense

PBS 3.1.3 Modes of Transmission

Multiple Choice

What is in a vaccine?

• Living Pathogens

• Dead Pathogens

• White Blood Cells

• Antibodies

Multiple Choice

The innate immune system_______

• Is present from birth

• Is acquired over time

Multiple Choice

What is the name of the hairlike projections that line the respiratory system?

• Cilla

• Flagella

• Enzymes

• Nucleus

Multiple Choice

Where are white blood cells produced?

• The brain

• The liver

• The blood

• The bone marrow

Multiple Choice

What type of cell destroys pathogens by engulfing them?

• Mast Cell

• Macrophage

• NK cell

• Red Blood Cell

Multiple Choice

Which responds more quickly?

• Acquired Immune system

• Innate Immune system

Multiple Choice

What type of cells produce antibodies?

• NK cells

• B Cells

• A cells

• Q cells

Multiple Choice

The markers that allow the immune system to recognize pathogens are called______

• antigens

• protogens

• macrophages

• cytogens

Multiple Choice

What is in a vaccine?

• Living Pathogens

• Dead Pathogens

• White Blood Cells

• Antibodies

Multiple Choice

The ability to defend against a pathogen by preventing its entry and/or development or by neutralizing its pathogenic cellular products.

• Immunity

• Herd Immunity

• Non-specific

• Innate

Multiple Choice

A form of artificially acquired immunity that occurs when the majority of a population, but not all, has been given a vaccine and becomes resistant to infection.

• Immunity

• Herd Immunity

• Non-specific

• Innate