Immunisation Flashcards
1
Q
Goal of vaccination
A
Strategic aim - Selective protection of the vulnerable, elimination through herd immunity
Programmatic aim - Prevent infection, transmission and death
2
Q
Passive immunity
A
- Maternal antibodies can protect baby for up to a year
- IG’s from donors are effective at first but disappear
3
Q
Active immunity
A
- Develop own immunity
- Triggers immune response
- Immunological memory
4
Q
Primary Immune response
A
- Develops in first few weeks following first exposure to an antigen - IGM
5
Q
Secondary immune response
A
- Antibodies are produced by B lymphocytes, antigen binds non-specifically to variable region of antibody molecule, triggering clonal expansion
- 1st wave of IgM production, followed by IgG production
- IgG binds to antigen and through simultaneous complement binding facilitates the destruction of the antigen-bearing microorganism
- When the infection resolves, levels of IgG decline
- However, one set of IgG producing B lymphocytes persists with ability to recognise that specific antigen = memory B cells
6
Q
Examples of Live organisms
A
MMR, BCG, Yellow fever, VZV – act like natural infection
7
Q
Inactivated organisms
A
pertussis, typhoid, IPV
8
Q
What is HNIG
A
Pooled plasma
9
Q
Advantages of live vaccines
A
- 1 dose often sufficient to induce long-lasting immunity
- Strong immune response evoked
- Local and systemic immunity produced
10
Q
Disadvantages of Live vaccines
A
- Potential to revert to virulence and for contamination
- Interference by viruses/vaccines and passive antibody
- Contraindicated in immunosuppressed
11
Q
Advantages of Inactivated/killed vaccines
A
- Stable
- Constituents clearly defined
- Unable to cause infections
12
Q
Disadvantages of Inactivated/killed vaccines
A
- Multiple doses
- Adjuvant needed - keep vaccine at injection site, activates antigen presenting cells
- Local reactions are common
