vaccines

Question 1

what does vaccination prevent from happening

Answer 1

the patient experiencing the disease before the primary response

Question 2

what do vaccines contain

Answer 2

antigens that cause your body to produce memory cells against particular pathogens without the pathogen causing disease
- means you can become immune without actually having the disease

Question 3

what is herd immunity and how does it work

Answer 3

• lots of individuals have immunity from having the vaccine
• reduces occurance of disease
• causes people without the vaccine to have less chance of catching the disease due to there being less people to catch it from

Question 4

what are antigens attached to in a vaccine

Answer 4

may be free or attached to a dead or weakened pathogen

Question 5

why are booster vaccines given`

Answer 5

to make sure memory cells are produced

Question 6

disadvantages of vaccines being taken orally

Answer 6

• break down of vaccine by enzymes in the gut or the molecules in the vaccine are too large to be absorbed into the blood

Question 7

antigenic variation helps some pathogens evade the immune system
explain how this happens…

Answer 7

• antigens can change their surface proteins
• this is antigenic variation
• memory cells produced the first time will not recognise the antigens so the immune system must carry out the primary response once again
• you get ill again as the primary response is slow
• makes it difficult to produce vaccines against the antigen

Question 8

how does antigenic variation effect the flu vaccines

Answer 8

• flu vaccine changes every year due to the protein surface of flu changing regularly
• new vaccines are developed and one is chozen every year that is most effective against the recently circulating flu virus
• governments then implement a programme of vaccination

Question 9

what is active immunity and how does it work- both natural and artificial examples

Answer 9

• when your immune system makes its own antibodies after being stimulated by an antigen
  -natural- catching the disease and making antigens
  -artificial- vaccinations giving you immunity

Question 10

what is passive immunity and how does it work- both natural and artificial examples

Answer 10

• given antibodies made by a different organism
• natural- baby becoming immune from antibodies recieved by the mother through the placenta and breast milk
• artificial- injections of antibodies such as tetanus jabs

Question 11

differences between active and passive immunity

Answer 11

active-
- requires exposure to antigen
- takes a while for protection to develop
- memory cells produced
- protection is long term as antibody is produced in response to complimentary antigen

passive
- doesnt require exposure to antigen
- protection is immediate
- memory cells arent produced
- protection is short term because antibodies are borken down