Vaccines

Question 1

The 2 types of immunisation

Answer 1

Active and passive

Question 2

What is passive immunisation?

Answer 2

The administration of pre-formed “immunity” from one person or animal to another person

Question 3

Limitation of passive immunisation

Answer 3

Only humoral (antibody) mediated

Question 4

Advantages of passive immunisation

Answer 4

Gives immediate protection, useful for immunocompromised patients

Question 5

Disadvantages of passive immunisation

Answer 5

Short-lived, possible transfer of pathogens

Question 6

Examples of passive immunisations

Answer 6

Human Tetanus Ig (HTIG)
Human Rabies Specific Ig
Human Hepatitis B Ig (HBIG)
Varicella Zoster Ig (VZIG)

Question 7

Active Immunisations can be…

Answer 7

Non-living vaccines and live attenuated vaccines

Question 8

What are the 3 main way to make a vaccine?

Answer 8

Using whole virus or bacterium
Parts that trigger the immune system,
Just genetic material

Question 9

Problems with whole killed vaccines

Answer 9

Organisms need to be grown in lab, can be difficult and expensive

Can cause excessive immunological responses

Immune responses are not always close to normal response to infection

Usually need at least 2 shots

Question 10

Examples of whole killed bacterial vaccines

Answer 10

Diptheria, tetanus, pertussis (whooping cough), cholera

Question 11

Examples of whole killed virus vaccines

Answer 11

Polio, influenza, Hep A, Covid, Rabies

Question 12

Attenuation

Answer 12

Where an organism is cultured in such a way that it does not cause disease when inoculated into humans. Loses pathogenicity but retains antigenicity (shape)

Question 13

Advantages of live attenuated vaccines

Answer 13

Immune response more closely mimics the real infection,

Lower dose required

Fewer doses required

Can often be taken orally

Question 14

Problems of live attenuated vaccines

Answer 14

Often impossible to balance attenuation and immunogenicity

Transmissibility

Question 15

Examples of live attenuated bacterial vaccines

Answer 15

Bacille Calmette-Guerin (BCG for TB)
Salmonella typhi

Question 16

Examples of live attenuated viral vaccines

Answer 16

Poliomyelitis
Vaccinia virus
Measles, Mumps and Rubella

Question 17

What are some reasons that there aren’t vaccines for all pathogens?

Answer 17

Pathogen too difficult to grow,
Killed pathogen not protective (shape change)
Impossible to obtain attenuated and suitably immunogenic strain

Question 18

Recombinant proteins

Answer 18

Genetically engineered and produced from bacteria, yeast, insect or mammalian cells

Question 19

Major difficulty for recombinant proteins

Answer 19

Hard to find protein or proteins that are protective and generate a strong enough immune response

Question 20

Synthetic peptides

Answer 20

Peptides synthesised directly using a machine - avoids the need for pathogen growth

Question 21

Live attenuated vectors

Answer 21

Composed of a safe living attenuated viruses that have inserted genes encoding foreign antigens, which are displayed to the immune system.

Question 22

Example of live attenuated viral vector

Answer 22

SARS-Co-V2

Question 23

DNA vaccines

Answer 23

A mammalian plasmid containing DNA that encodes for the foreign protein of interest is injected directly

Question 24

mRNA vaccines

Answer 24

mRNA of the target foreign protein is synthesised in vitro, complexed with lipid nanoparticles that stabilise and protect the mRNA from degradation, allowing hte mRNA to cross the plasma membrane.

mRNA translated and protein presented on surface with MHC, stimulates immune response

Question 25

T-independent antigens

Answer 25

bacterial capsular polysaccharides cannot be processed and presented on MHC class II

Question 26

When do kids take the PCV (pneumococcal conjugate vaccine)?

Answer 26

2 months, 4 months, 13 months

Question 27

When do babies get doses of MenC vaccine?

Answer 27

3 and 4 months

Question 28

Is BCG routinely given to teenagers?

Answer 28

No, not anymore, targeted for at-risk infants