Vaccination/TB

Question 1

How do vaccines work

Answer 1

Vaccines work because if you are vaccinated, immune system responds to vaccine as it would to disease. Antibodies are produced and memory cells ensure lasting protection so if you come into contact with pathogen, you can rapidly destroy it before onset of symptoms.

Question 2

What may vaccines contain

Answer 2

Vaccines may contain
Attenuated viruses - weakened viruses
Killed bacteria
Toxin in a harmless form
Antigen bearing fragment of pathogen

Question 3

What are boosters and why may they be necessary

Answer 3

Boosters are extra vaccinations after Initial vaccination to ensure lasting immunity. They may be necessary to protect against new strains of virus e.g influenza

Question 4

What is herd immunity

Answer 4

Herd immunity is when enough people are immunised so disease is less likely to be transferred from 1 person to another and so there is less disease in a community as a whole. This means anyone who could not get vaccine is still protected

Question 5

What are potential dangers of vaccine

Answer 5

Dangers of vaccines are can cause mild soreness, fever or general feeling of being unwell

Question 6

When will antibodies be present

Answer 6

Antibodies will be present when antigen is present

Question 7

How can you tell if a study is reliable

Answer 7

A study is reliable if:
Uses a large sample size
Error bars don’t overlap (if overlap, unreliable)
Uses control

Question 8

When can reliability not be deduced

Answer 8

Reliability can’t be deduced when
No numbers in sample are given
No error bars
No statistical evidence
No control

Question 9

How does TB evade body defences

Answer 9

TB evades body defences by :
M.tuberculosis has very thick, waxy cell walls which makes destruction in macrophages very difficult so some M.tuberculosis bacterium survive in macrophages (tubercules, which are dormant).
Overtime, mutations may occur to evade immune system e.g change in shape of receptor (evolution by natural selection), ability to use different food sources, ability to infect cells more easily.
Suppresses T helper cells. T helper cells produce cytokines activate B cells and T cells which reduces antibody production. Decrease T killer cells attacking infected cells.

Question 10

How does HIV evade immune response

Answer 10

HIV evades immune response by:
Found inside T helper cells so not recognized by antibodies, phagocytes
Attack T helper cells leading to decreased antibodies
Frequent mutations in HIV
Rapid reproduction of HIV