vaccinations and immunisation

Question 1

what are the 6 different types of vaccine?

Answer 1

• Live
• Attenuated
• Killed
• Extract
• Recombinant
• dna/Mrna

Question 2

what is the Pasteur Principle?

Answer 2

ISOLATE pathogen
INACTIVATE pathogen
INJECT people with vaccine.

Question 3

what are the 6 essential characteristic of vaccines?

Answer 3

1 - must provide protection without risk of causing the disease or severe side effects
2 - protection should be long lived
3 - should stimulate correct immune response
4 - stimulate neutralising antibodies to prevent re-infection.
5 - stable for long term storage and transport
6 - economically affordable for widespread use.

Question 4

Live vaccine

Answer 4

organisms capable of normal infection and replication. not used against pathogens that can cause severe disease.

Question 5

attenuated vaccine?

Answer 5

organism is live, but ability to replicate and cause disease reduced by chemical treatment or growth addition in non-human cell lines (measles, mumps, rubella)

Question 6

killed vaccine?

Answer 6

organism killed by physical or chemical treatment. Incapable of infection or replication, but still able to provoke strong immune response

Question 7

extract vaccine?

Answer 7

materials derived from disrupted or lysed organisms, eg - capsular polysaccharides. used when risk of organism surviving inactivation steps

Question 8

recombinant vaccine?

Answer 8

genetically engineered to alter critical genes. often can infect and replicate but does not induce associated disease.

Question 9

DNA vaccine?

Answer 9

naked DNA injected. Host cells pick up DNA and express pathogen proteins that. stimulate immune response.

Question 10

what vaccine is best and most likely to be used?
why is that?
what is the paradox?

Answer 10

live or attenuated

• paradoxically, the safer the vaccine the less effective it is going to be.
• living and attenuated organisms express proteins and stimulate the immune response in a manner which most closely resembles normal infection.

Question 11

why have vaccination rates fallen?

Answer 11

there is huge herd immunity.
- the beneficial impact of vaccination is so clear that some people are not aware of the dangers anymore.
There is the possibility that not everyone needs immunised because there are enough people vaccinated that the chances of an unprotected person meeting a pathogen becomes small.

Question 12

what is herd immunity?

Answer 12

a pool of unimmunised individuals that can become a victim to disease.
when a large part of the population of an area is immune to a specific disease

Question 13

what is in the DTaP/IPV/Hib vaccine?

Men C vaccine?

DTaP/IPV?

Td/IPV?

Answer 13

1) Diphtheria, tetanus, pertussis, inactivated polio vaccine, heamophilus influenza type B.

2) meningococcal C conjugate

3) booster vaccine for diphtheria, tetanus, perstussis, polio.

4) booster vaccine for tetanus, diphtheria, polio.

Question 14

what are the origins for:

HIV?
Ebola?
SARS?
vCJD?

Answer 14

HIV= non human primate origin

Ebola = handling of gorilla, chimp, duikers

SARS= palm civets and racoon dogs

vCJD= food chain, rendering

Question 15

what do dendritic cells express?

what happens when CpG is included with HepB or flu vaccines?

Answer 15

patern recognition receptor (PRR), these are members of the toll-like receptor family.

DC sit on the interface between innate immunity and specific immunity.
Activation of DC’s increase the their ability to capture and process antigen and immunogens, and also attract and activate T cells.
When CpG is included with herb or flu vaccines the result os increased antibody or INF-y secretion.

Question 16

describe the stages of the activation of dendritic cells?

Answer 16

1- encounters antigen in periphery, becomes activated

2- migrates to lymph node

3- activates T cells to become effector cells.

Question 17

when are pneumococcal and flu vaccine offered?

Answer 17

• the pneumococcal vaccine is offered to 65yrs and over
• flu vaccine is offered to the elderly and at risk individuals. in the region of 11 million people are within the recommended group.

Question 18

when are travel vaccinations changing?

what are 3 examples of travel vaccination recommendation from 2005?

Answer 18

Travel vaccinations are constantly changing
3 examples of travel vaccination recommendations from 2005:
1) Avian Flu, West Nile Virus (USA, Canada and Portugal)

2) Marburg Virus (Angola)

3) Poliomyelitis (Nigeria)

Question 19

What is reverse vaccinology?

Why was this useful for meningococcus B?

Answer 19

• Reverse vaccinology is the technique of identifying the protein exposed on the surface of pathogens by sequencing their genome in order to find new vaccines
• Originally, the microorganism itself was used to create vaccines
• This is useful for Meningococcus B, because the capsular polysaccharide antigen that would normally be a good target looks almost identical to a sugar on NCAM, an important neuronal membrane protein.
• Antibodies could cause autoimmunity due to this

Question 20

what are examples of challenges in development of vaccination?

Answer 20

Examples of challenges in development of vaccinations:
1) 1918: Spanish Flu, 20-40 million dead

2) 1957: Asian Flu, 1-4 m dead

3) 1968: Hong Kong, 4m dead

4) Latest potential threat is H5N1.
* First reappeared HK 1997, infected 18, killed 6.
* Multiple cases in Far East
* 100 million fowl culled to prevent spread.

5) SARS coronavirus: Feb to July 2003
* infected 8,098 people, killed 774.

6) West Nile Virus: NY 1999
* Within 4 years spread across most of USA, infected 9,862 people, 264 deaths in 2003

Question 21

What do vaccines have to engage in the immune system?

What do dendritic cells express?

How do dendritic cells work?

Answer 21

It is important that there is a strong dendritic cell activation in the immune system from vaccines
Dendritic cells express Pattern Recognition Receptors (PRR), members of the Toll-like receptor Family (TLR)
When dendritic cells meet something pathogenic, they grab a hold of the pathogen, and move it to the lymph node to start the process of activating T and B cells
This results in a big upregulation of the immune response

Question 22

Are dendritic cells (DC) innate or adaptive immunity?

What does activation of DCs increase?

What is CpG?

What does it help stimulate? What is IFN gamma?

Answer 22

Dendritic cells (DC) sit at the interface between innate immunity and specific (adaptive) immunity
Activation of DC’s vastly increases their ability to capture and process antigen and immunogens, and also attract and activate T cells.
CpG is an adjuvant that can be used in HepB or flu vaccines
When used, it helps stimulate increase antibody production of IFN-gamma secretion
Interferon‐gamma (IFN‐γ) is a cytokine that plays an important role in inducing and modulating an array of immune responses