types of immunity

Question 1

natural active immunity

Answer 1

• immune system meets pathogen and antibodies are formed
• immune system produces memory cells so when pathogen is met again, the immune system recognises the antigens and can destroy it
• body itself has acted to produce antibodies/memory cells

Question 2

natural passive immunity

Answer 2

• new-born baby gets passed antibodies across the placenta by the mother
• baby has same level of antibody protection against disease as mother
• this is natural passive immunity and it lasts until the immune system of the baby begins to make its own antibodies

Question 3

artificial passive immunity

Answer 3

• antibodies are formed in 1 individual, extracted and injected into another individual
• gives temporary immunity

Question 4

artificial active immunity (vaccination)

Answer 4

• immune system is stimulated to make its own antibodies to a safe form of antigen which is injected
  1. pathogen is made safe so that it is intact but not at risk of infection e.g. killed/inactive pathogens, attenuated strains of live pathogens
  2. small amounts of safe antigen are injected
  3. primary immune response is triggered by the foreign antigens and antibodies/memory cells are produced
  4. if body encounters live pathogen, secondary immune response is triggered to destroy pathogen rapidly before symptoms are suffered

Question 5

what is an epidemic

Answer 5

when a communicable disease spreads rapidly to a lot of people at a local or national level

Question 6

what is a pandemic

Answer 6

when a communicable disease spreads rapidly across a number of countries/continents

Question 7

what is herd immunity

Answer 7

when a significant number of people in the population have been vaccinated so there is minimal opportunity for an outbreak to occur