Vaccinations

Question 1

what are the aims of vaccination?

Answer 1

→ protect from infectious diseases
→ to produce ‘riskless immunity’ i.e. disease is not contracted
→ to produce IMMUNOLOGICAL MEMORY

Question 2

vaccination is very specific to a single _____

Answer 2

antigen

Question 3

currently what country are developing a HVTN702 vaccine against HIV?

Answer 3

south africa

Question 4

how many children die from vaccine preventable diseases in 2008 and why?

Answer 4

1.5 million,
due to:
→ no access to vaccine
→ refusal to vaccine

Question 5

what needs to be balanced when considering vaccinations?

Answer 5

risk of vaccine effects and disease contraction

Question 6

MMR vaccine is 1/1million for getting encephalitis (inflammation of the brain) what are the encephalitis rates if measles and mumps is contracted if no vaccine is given?

Answer 6

measles = 1/2000,
mumps = 1/300

Question 7

DPT vaccine has no proven deaths. what are the death rates for diphtheria, pertussis, tetanus?

Answer 7

diphtheria = 1/20
pertussis = 1/200
tetanus = 3/100

Question 8

what are the two different types of immunity?

Answer 8

active and passive

Question 9

describe active immunity

Answer 9

protection developed by a persons own immune system → requires exposure to pathogen

usually takes days/weeks to develop but is usually permanent

can be natural → contracting disease OR acquired → vaccination exposure

Question 10

describe passive immunity

Answer 10

immediate protection transferred from one individual to another → transfer of IgE antibody

short lived → weeks/months

can be natural (transplant) or acquired
e.g. breast milk to protect babies

Question 11

the more _____ a vaccine is to a pathogen the more _____ the vaccine is

Answer 11

similar, effective

Question 12

what are the different formulations of active immunisation?

Answer 12

live pathogen, killed micro-organism, microbial extracts, vaccine conjugates, toxoids

Question 13

this formulation is attenuated with its virulence genes removed

Answer 13

live pathogen

Question 14

what two formulation methods produce lots of different antibodies for multiple antigens present?

Answer 14

live pathogen and killed micro-organism

Question 15

what formulation has 1 antigen injected and is efficient for the body but may be ineffective if the pathogen modifies?

Answer 15

microbial extracts

Question 16

what formulation has a polysaccharide attached to stop the virus from hiding antigens?

Answer 16

vaccine conjugates

Question 17

can combine a weak antigen with a strong antigen so immune system has a stronger response to the weak antigen

Answer 17

vaccine conjugates

Question 18

only applicable to bacteria that produce toxins by injecting an inactivated form of the toxin. what formulation is this?

Answer 18

toxoid

Question 19

describe how small pox was the first virus to be eradicated

Answer 19

Jenner 1796 → identified similarity between smallpox virus and cowpox virus

→ sufferers with non fatal cowpox did not become infected with fatal smallpox
→ she infected a boy with cowpox then smallpox → he didn’t contract smallpox

Question 20

smallpox stats:
1800s =
1930s =
1940s = 
1958 = 
1977 =

Answer 20

1800s = compulsory vaccination
1930s = last natural UK case
1940s = last natural US case
1958 = WHO program requiring worldwide cooperation
1977 = last wild case

Question 21

give reasons why smallpox eradication was so successful?

Answer 21

→ no animal reservoir for smallpox virus
→ few subclinical cases → symptoms were always evident
→ infectivity does not procede overt (obvious) symptoms

→ 1 variola serotype (strain) → so 1 antigen only requiring 1 antibody → 1 vaccine

→ effective vaccine → lifelong immunity
→ major government commitment

Question 22

what are the problems with developing vaccines?

Answer 22

→ different viruses may cause similar disease (common cold)
→ virus alteration/mutation
→ rapidly changing properties
→ immune system may be unable to detect some viral hidden antigens

Question 23

what are the 2 different types of virus alteration?

Answer 23

antigenic drift and antigenic shift

Question 24

antigenic drift =

Answer 24

accumulation of mutations

Question 25

antigenic shift =

Answer 25

recombination → 2 or more different strains or different viruses combine to form a new pathogen subtype
(have a mixture of both strains surface antigens)

can result in pandemics

Question 26

why is the 2nd antigen encounter more rapid in immune response than the 1st antigen encounter?

Answer 26

1st = slow B cell product of antibodies (initially IgM)

2nd = more rapid response due to presence of memory B cells