Bacterial and Viral Vaccines

Question 1

Who first tested out the smallpox vaccine?

Answer 1

Benjamin Jesty - 1774

Edward Jenner 1796 (MORE POPULAR)

Question 2

After the smallpox vaccine, when was the next vaccine made?

Answer 2

Almost 100 years later in 1885

Question 3

What is the goal of immunisation?

Answer 3

To allow the body to protect itself from infectious diseases

Question 4

What are the two types of immunity?

Answer 4

Innate

Acquired

Question 5

What are the two types of acquired immunity?

Answer 5

Active - Made in own body

Passive - Ready made antibodies

Question 6

What are the subcategories of active immunity?

Answer 6

Natural (disease exposure)

Artificial (Immunisation)

Question 7

What are the subtypes of passive immunisation?

Answer 7

Natural - maternal antibodies

Artificial - exogenous antibodies

Question 8

At what R0 (the no. of people 1 sick person can affect) is transmission halted?

Answer 8

If effective R0 is reduced < 1 then transmission is halted

Question 9

What is herd immunity?

Answer 9

Form of immunity that occurs when vaccination of a significant proportion of a population provides a measure of protection for individuals that are not immune.

Question 10

What is the Herd immunity threshold?

Answer 10

Percentage of fully immune individuals required to stop the spread of disease

Question 11

How do you calculate the Herd Immunity threshold?

Answer 11

HIT = 1 -1/R0

Question 12

What are the cells in the innate immune system?

Answer 12

Macrophage
Dendritic cell
Mast cell
NK cell
Granulocytes
Complement proteins

Question 13

Which cells are present in the adaptive immune response?

Answer 13

B cells - antibodies

T cells - CD4/CD8

Question 14

What cells overlap between the innate and acquired response?

Answer 14

NK cells

gamma delta T cell

Question 15

How does the body respond to a vaccine?

Answer 15

APCs present part of the antigen on the cell surface

APCs present antigen to naive T cells in the LN where they are activated

B cells activate in response to antigens - some B cells become plasma cells which produce specific antibodies and neutralise infection + Ab dependent cellular cytotoxicity

Attenuated Vx = T cell virus clearance

Memory cells produced

Question 16

Does natural immunity occur after infection?

Answer 16

Microbial components give rise to a protective immune response

Vaccines need adjuvants to make it more potent

Question 17

What are inactivated vaccines?

Answer 17

Whole microorganism destroyed

[by heat, chemicals, radiation or antibiotics (e.g. Influenza, cholera, polio)]

Question 18

What are the advantages of inactivated vaccines?

Answer 18

• Stable
• Constituents clearly defined
• Unable to cause the infection

Question 19

What are the disadvantages of inactivated vaccines?

Answer 19

• Need several doses
• Local reactions common
• Adjuvant needed
• Shorter lasting immunity

Question 20

What are attenuated vaccines?

Answer 20

• Live organisms modified to be less virulent
• Examples
• Measles, mumps, rubella, yellow fever

Question 21

What are toxoid vaccines?

Answer 21

Inactivated toxic components

Examples: Tetanus, diphtheria

Question 22

What are subunit vaccines?

Answer 22

• Protein component of the microorganisms or synthetic virus like particles.
• Lacking viral genetic material and unable to replicate.
• Examples: Hepatitis B, HPV

Question 23

What is a conjugate vaccine?

Answer 23

• Poorly immunogenic antigens paired with a protein that is highly immunogenic (adjuvant)
• Examples: Haemophilus influenzae type B

Question 24

What is a heterotypic vaccine?

Answer 24

Pathogens that infect other animals but do not cause disease or cause mild disease in humans
• Examples: BCG

Question 25

What is a viral vectored vaccine?

Answer 25

• Use a modified virus (e.g. adenovirus) to deliver
genetic code for an antigen.
• Examples: Ebola, Janssen and AZ COVID vaccines

Question 26

What is a nucleic acid vaccine?

Answer 26

• Use DNA/RNA from the pathogen.

* Examples: Pfizer and Moderna COVID vaccines

Question 27

What is the difference between monovalent and multivalent?

Answer 27

Mono = 1 antigen
Multi = multiple antigen (e.g. pneumococcal which has 21 antigens)

Question 28

What are the components of a vaccine?

Answer 28

Active components
Adjuvants
Antibiotics
Stabilisers
Preservatives
Trace components

Question 29

Serious reactions are uncommon

Answer 29

Serious reactions are uncommon

Question 30

Why are vaccination programmes important?

Answer 30

• Vaccine should be administered before the age
related peak incidence of the disease.
• Targeted vs widespread.
• To eliminate a disease the effective R0 needs to be <1.
• ?requirement for catch up campaigns.
• Endemic vs Epidemic infections.

Question 31

What are the barriers to vaccination?

Answer 31

Access
money
Anti vax campaigns

Question 32

What are the prerequisites for successful disease eradication?

Answer 32

• No animal reservoir
• Antigenically stable pathogen with only one (or small number of) strains
• No latent reservoir of infection and no integration of pathogen genetic material into host genome
• Vaccine must induce a lasting and effective immune response
• High coverage required for very contagious pathogens

Question 33

Do vaccines have a good impact?

Answer 33

Yes

Question 34

What are the side effects of vaccines?

Answer 34

• Adenoviral vectored vaccines
• VITT
• 14.2 per million doses
• CLS
• Pfizer
• Lymphadenopathy
• Myocarditis