L15 - Vaccination

Question 1

What are the 3 occasions that we receive vaccines?

Answer 1

Childhood vaccination

Travel vaccines

Vaccines for the elderly

Question 2

What was the hysteria surrounding the MMR vaccine?

Answer 2

linked MMR vaccine to autism - NOT TRUE

Question 3

What cells mediate adaptive immunity?

Answer 3

Lymphocytes

Question 4

What cells are required for the initiation of an adaptive immune response?

Answer 4

Dendritic cells

Question 5

How does immunological memory confer longer lasting protection?

Answer 5

more responder cells available

more efficient antigen recognition

Rapid migration to tissues and lymph nodes

More effecting function

Longer lasting

Question 6

What antiboides are important for humoral immunity against BLOOD BLORNE pathogens?

Answer 6

IgG

Question 7

What antibodies are important for humoral immunity against MUCOSAL pathogens

Answer 7

IgA

Question 8

What do immunoglobulins do?

Answer 8

neutralise antigens - block interaction with target

• bind bacterial toxins
• prevent viruses attaching to surface of host cell
• prevent bacteria attaching to surface of host cell

Question 9

How do immuoglobulins opsinise antigens for uptake by phagocytes?

Answer 9

Fc receptors bind to Fc region of immunoglobulin - antigen complexes

antigen complex -> degradation of antigen

Question 10

How do immunoglobulins activate the classical complement pathway?

Answer 10

complement mediated neutralisation

complement mediated lysis

Phagocytosis via complement receptors

Question 11

How do CD4 T cells promote antibody production?

Answer 11

Help interactions - CD40/CD40ligand

leads to B cell proliferation & differentiation

Question 12

Why are CTLs (CD8) important for INTRACELLULAR pathogens?

Answer 12

recognises virus infected cells by peptides displayed on MHC

Question 13

Why is it useful to have a vaccine that activates CD8 and CD4?

Answer 13

catch virus extracellularly and intracellularly

Question 14

What is dendritic cell maturation activated by?

Answer 14

danger signals

Question 15

what are DIRECT danger signals recognised by?

Answer 15

TLRs 4 and 9

Question 16

What are indirect signals?

Answer 16

secretion triggered by pathogens

Question 17

What molecules are secreted by macrophages in response to microbial molecules?

Answer 17

TNF-a

IL-1b

Question 18

What are adjuvants?

Answer 18

component of vaccine preparation that amplifies adaptive immune response

Question 19

How do adjuvants act?

Answer 19

directly or indirectly to provide signal to promote dendritic cell activation

Question 20

What are alum-based adjuvants?

Answer 20

precipitate of aluminium hydroxyphosphate

Question 21

How do alum-based adjuvants act?

Answer 21

activate inflammasome - IFNb

cause neutrophil infiltration & DAMP release

Question 22

What do alum-based adjuvants increase?

Answer 22

DC migration to lymph nodes

T cell interactions

antigen presentation

Question 23

What immunity is alum poor at promoting?

Answer 23

CTL immunity

GOOD AT HUMORAL IMMUNITY

Question 24

Other adjuvants in clinical use?

Answer 24

MF59 - oil-in-water, squalene

GSK Adjuvant System 04 (AS04)

Question 25

What is the MF59 adjuvant?

Answer 25

induces monocyte recruitment to injection site increases DC migration to lymph node

Question 26

What is the AS04 adjuvant?

Answer 26

combines alum with monophosphoryl lipid A (MPL) MPL = endotoxin - less toxic than LPS - still act via TLR4 increase co-stimulatory molecule expression

Question 27

What are live attenuated vaccines?

Answer 27

retain antigens introduce mutation in cell culture to reduce virulence often have inherent adjuvant properties

Question 28

Cons of live attenuated vaccines?

Answer 28

can revert to virulent form don't give to immunodeficient subjects

Question 29

Examples of diseases treated by live attenuated vaccines?

Answer 29

Rabies BCG Sabin Polio vaccine

Question 30

What is the Sabin Oral Polio vaccine?

Answer 30

3 attenuated strains mutate by passaging through monkey kidney epithelial cells transiently infect - vaccine colonise intestine - stimulates IgA production

Question 31

What reduces virulence in the Sabin Oral Polio vaccine?

Answer 31

nucleotide changes

Question 32

What are inactivated (killed) vaccines?

Answer 32

unable to divide pose less risk that live attenuated cannot revert to virulent strain - better if immunodeficient

Question 33

Cons of inactivated vaccines?

Answer 33

do not persist as long as live vaccine may not induce lymphocyte production to same extent

Question 34

Examples of inactivated vaccine?

Answer 34

influenza typhoid hepatitis A Salk Polio vaccine

Question 35

What is the Salk polio vaccine?

Answer 35

3 diff. polio strains inactivated by formaldehyde administered by intramuscular injection = less mucosal immunity than Sabin

Question 36

What are subunit vaccines?

Answer 36

contain A PART OF THE PATHOGEN: - associated proteins - inactivated toxins (toxoids) - non-protein antigens

Question 37

How can subunit vaccines be made more immunogenic?

Answer 37

multiple doses to extend period of stimulation use adjuvants

Question 38

What does the HPV vaccine contain?

Answer 38

L1 capsid proteins - VLPs Alum adjuvant non-infectious as no nucleic acid

Question 39

What are toxoids?

Answer 39

toxin treated with formaldehyde to produce inactive toxoid - cannot cause disease needs adjuvants to stimulate immunity - alone is not sufficient to give a signal to activate DCs

Question 40

What are conjugate vaccines?

Answer 40

capsular polysaccharides conjugated to proteins e.g. toxoids help from toxin specific T + B cells specific for capsular polysaccharides

Question 41

Examples of conjugate vaccine?

Answer 41

Haemophilus influenzae type B serogroup C N. Meningitis

Question 42

SARS-CoV-2 vaccine?

Answer 42

SPIKE PROTEIN Pfizer - BNT162b2 mRNA encoding S-protein lipid nanoparticles - BNT162b2 Astra-Zeneca - adenoviral vector- does not replicate but expressers S-protein