Vaccination

Question 1

Goal of vaccination

Answer 1

Generate long lasting and protective immunity
Induce memory without causing disease, so pathogen induce a secondary memory not a primary.
-Antibody
-T cell
-Systemic
-Mucosal

Question 2

Herd immmunity

Answer 2

Results from a successful vacicination program
Lowering the number of susceptible people
Decreases the natural reservoir
Reduces the probability of infection

Even unvaccinated people are protected as their chances of encountering the pathogen is decreased.

Question 3

Types of vaccination

Answer 3

Active:
Trigger the immmune response to develop immunity and immunological memory
Live attenuated
Inactivated

Question 4

Live attenuated form

Answer 4

Inactivated preparation e.g Flu
Detoxified exotoxins e.g tetanus
Extracts of a microorganism
(from organism, or recombinant DNA technology)

Method:
Take virus of interest
Culture with different type of cell (monkey)
virus mutates, changes specificity (cell proteins)
Virus is specialised towards monkey cells, they do not apply toxicity towards human cells anymore.

Method2:
Extract the virulent gene, but the core proteins e.g receptor binding proteins, and function to remain alive remains intact.

e.g: Bacillus Calmette Guerin BCG

Question 5

Attenuation

Answer 5

Loses virulence but maintains antigenicity. Immune response is strong, but toxicity is removed.

Question 6

Properties of live vaccines

Answer 6

Most dangerous give the most durable immunity
They do not last as long as natural infection
They are live, they themselves could mutate int he future, can mutate and revert to the wild type form (virulent form)

Question 7

Inactivated viruses

Answer 7

done by heat or by formaldehyde (keeps the structure)
They may require a primary series of injections as they will take a while to develop response.
Duration last for months-years
Often adsorbed onto an adjuvant to enhance the Ab response, it enhances the information and anti-inflamitory response.
It does not divide

Question 8

Purified molecules/Subunit vaccines

Answer 8

Inactivated exotoxins, removed subunits thats virulent.
Capsular polysacharides
Surface glycoproteins

Essentially, they are just the proteins of interest.

Question 9

Passive immunisation

Answer 9

Delivery of preformed antibody, associated with deficiencies. Toxin or venom exposure with immediate threat of life
Exposure of pathogens where DEATH > IMMUNE response

Question 10

Route of vaccination

Answer 10

most vaccines are given by injection

• painful/unpopular
• Reduces vaccine uptake, can degrade in different ways
• Expensive, disposable items
• Laborious
• Doesn’t mimic how the pathogen gains entry.

Preferential:
Induce host defence at site of pathogen entry
Stimulation of mucosal immunity

Question 11

Good example of route - OPV

Answer 11

Oral polio vaccine
3 attenuated strains
Requires boosters - each virus interfres with each other replication
Colonize intestine and induce IgA
Induces IgG and IgM

Question 12

Adjuvants

Answer 12

Help immune response
Added to vaccines to enhance immune response, oftenly used for purified molecules.
Main used: ALUM (last 80 years)
-enhances of inflammation
-mixed in an emulsion
-Slow release/sustained stimulation.

Other:
MF59, oil in water
-slow antigen delivery

AS04, ALUM+TLR4 agonist

• encourages TH1 responses
• used in vaccines against HPV and HSV-2

Both increases Ab production.

Question 13

Newer strategies.

Answer 13

Produce multi valent vaccine

Miscelles, lipid vesicles or immunostimulating complexes.