Lecture 3 - Immunisation and immunotherapy

Question 1

Briefly describe how active immunisation works

Answer 1

administering antigen induces antibody and/or T cell response specific to the given antigen. Both systemic and mucosal immunity can be induced. protection not immediate

Question 2

Briefly describe how passive immunisation works

Answer 2

administer pre formed antibody in order to protect from disease. immediate protection but no immunological memory or immune response generated

Question 3

Which immunoglobulins are generated at each stage of antibody responce

Answer 3

primary is IgM and secondary is mainly igG

Question 4

Describe a live attenuated vaccination

Answer 4

one dose of organism who’s virulance has been reduced - organism multiplys in host and immune response same as that of natural infection.
systemic and mucosal

Question 5

Describe the risks of a live attenuated vaccine

Answer 5

• severe infection in immunocompromised
• organism can revert to normal virulence
• storage conditions are critical

Question 6

3 examples of a live attenuated vaccine

Answer 6

MMR, BCG, oral polio

Question 7

Describe a killed vaccination

Answer 7

several doses of inactivated organism - immune response generated. only systemic reaction
stable to store. have to administer with adjunctive which boost immune system

Question 8

Give and example of an adjunctive used in vaccination

Answer 8

aluminium hydroxide - NOT antigens

Question 9

Name the risks of a killed vaccination

Answer 9

• risk of reaction

- the inactivated form may change the structure of the organism

Question 10

Give 3 examples of killed vaccination

Answer 10

killed polio, influenza, pertussis

Question 11

Describe a subunit vaccination

Answer 11

parts of an organism are administered in several doses with adjuvant. usually only a systemic response. body doesn’t mimmic natural response but does induce response to prevent disease

Question 12

Give 4 examples of a subunit vaccination

Answer 12

Gr C menningococcal, tettanus, Hep B, hib

Question 13

Describe subunit conjugate vaccinations

Answer 13

two subunits are bound in order to activate both B cells and T cells. B cells cannot divide unless activated by T cells. e.g. diptheria protein and mennincococcal Gr C polysacharide

Question 14

Describe some contraindications for vaccines

Answer 14

• acute illness or allergy to previous doses
• live vaccines shouldn’t be used in pregnancy or in immunocompromised (primary e.g. HIV or secondary e.g. steroids chemo)
• allergy to stuff in vaccine e.g. influenza vaccine made with extracts of egg

Question 15

When should live vaccine doses be given and why

Answer 15

at the same time or several weeks apart (too close together and immune system is suppressed and wont respond to second dose)

Question 16

Which vaccine cant you give if the patient is on antibiotic therapy

Answer 16

typhoid

Question 17

Which vaccine is given to splenectomy patients and why?

Answer 17

pneumovax against pneumococcus. no spleen increases susceptibility

Question 18

What is Human immunoglobulin replacement therapy ?

Answer 18

IgGs derived from plasma of 1000 doners. must be 90% intact. must be biologically active and must no have any inflammatory mediators or infectious agents.

Question 19

What is in commercial IVIG

Answer 19

lots of antibodies from lots of bacteria/virus’

still active to neutralise toxins and activate compliment

Question 20

When would commercial IVIG be given?

Answer 20

Primary immunodeficiencies:
-B cells e.g. x linked agammaglobulinaemia or hyper igM
-T cell deficiency (as activates)
Secondary immunodeficiencies:
- chronic lymphocytic leukaemia or multiple myeloma
- HIV in children with recurrent infections
- premature babies with recurrent infections
- early onset neonatal sepsis

Question 21

How are specific immunoglobulin preparations produced in replacement Ig therapy

Answer 21

either plasma pre screened for high titres of antibody

or volunteers vaccinated first so prod loads of ABs e.g. rabies

Question 22

Give examples of hyperimmune immunoglobulin for post exposure treatment / prophylaxis

Answer 22

rabies (bitten), RSV, Hepatitis (e.g. needle stick injury), tetanus, VZV( if mother develops chicken pox within 5 days of birth, CMV if immunosuppressed

Question 23

What are monoclonal antibodies?

Answer 23

Artificially produced antibodies of a single specificity derived from a single B cell clone.

Question 24

Name three positives to using monoclonal antibodies

Answer 24

endless supply
highly specific and more potent than immune sera
reduce risk of transferring infection

Question 25

Name 4 biological activites of cytokines

Answer 25

stimulation of cells in immune system
stimulation of inflammation
stimulation of haematopoiesis
anti-viral and anti-proliferative activities

Question 26

Describe two occasions when interferon alpha therapy is appropriate

Answer 26

Hepatitis B - 50% response rate though

Hepatitis C in combination with Ribavirin (or pegintereforon alpha)

Question 27

How does interferon alpha cytokine therapy reduce viral activity

Answer 27

inhibiting viral replication and protein synthesis

stimulating antiviral immune responce

Question 28

How are circulating neutrophil levels enhanced in cytokine therapy ? Why is this a benefit and in what?

Answer 28

1) granulocytes CSF and granulocytes and macrophages CSF
2) -reduces febrile neutropenia in cytotoxic chemo
- reduces duration of neutropenia in myeloblative therapy followed by BMT

Question 29

Why is interferon gama used in cytokine therapy? example of when this is used and how it works?

Answer 29

enhances phagocyte function e.g. in chronic granulomatous disease
- CGD phagocyte NADPH oxidase gene defect therefor reactive oxygen metabolites not generated (needed for killing bac). interferon gama upregs NADPH oxidase