Cells: Cell Recognition & the Immune System - Vaccines

Question 1

What are the two types of immunity?

Answer 1

• Active immunity

- Passive immunity

Question 2

What are the two sub-types of immunity?

Answer 2

• Natural

- Artificial

Question 3

What is active immunity?

Answer 3

• This is the type of immunity you get when your system makes its own antibodies after being stimulated by an antigen

• Natural - when you become immune after catching a disease
• Artificial - when you become immune after you’ve been given a vaccination

Question 4

What is passive immunity?

Answer 4

• This is the type of immunity you get from being given antibodies made by a different organism - your immune system doesn’t produce its own antibodies

• Natural - baby becomes immune due to transfer of maternal antibodies through the placenta or in breast milk
• Artificial - being injected with antibodies from someone else

Question 5

What are the differences between active and passive immunity?

Answer 5

• Active immunity

• Requires exposure to antigen
• Takes a while for protection to develop
• Memory cells are produced
• Protection is long-term

• Passive immunity

• Doesn’t require exposure to antigen
• Protection is immediate
• Memory cells aren’t produced
• Protection is short-term (few weeks)

Question 6

Explain how vaccination leads to immunity

Answer 6

• Antigens of pathogens are introduced to the body - by injection or orally
• Antigens stimulate the immune response
• Response is slight as only a small amount of antigen has been introduced - if the pathogen is used it has been attenuated (weakened)
• Memory cells are introduced
• These remain in the blood and allow a greater, more immediate response to future infections of that antigen

Question 7

Explain the concept of herd immunity

Answer 7

• Not everyone can be vaccinated
• The more people are immune to a pathogen, the lower the likelihood of (non-immune) people making contact with a pathogen
• Those with disease spread the pathogen more rapidly
• If vaccinated, less disease therefore less spread

Question 8

Ethical issues surrounding the use of vaccines

Answer 8

• All vaccines are tested on animals before being tested on - some people disagree with animal testing
• Animal based substances may be used to produce a vaccine - some people disagree with this
• Testing vaccines can be risky - can have harmful side effects
• If there was an epidemic of a new disease who should get the vaccine first?