M11: Prophylactic Immunisation Flashcards
What is natural active immunity?
Follows clinical or subclinical infection
What is artificial active immunity?
Induced by vaccination
What is natural passive immunity?
Due to trans-placental maternal IgG antibody which protects child for first few months of life
What is artificial passive immunity?
By injection of pre-formed antibody derived from serum of man or animals
What are horse antitoxins used to treat?
Treatment in suspected cases of diphtheria and botulism
What is HNIG?
- Human normal immunoglobulin
- Protective levels of antibody to a range of diseases present in pooled normal human serum
What are the properties of an ideal vaccine? (6)
- Promotes effective immunity
- Confers lifelong protection
- Safe (no side effects)
- Stable
- Cheap
- Seen to be good and effective
What is a toxoid vaccine?
- Use of inactivated toxin
- Useful for conditions where symptoms of a disease can be attributed essentially to the effects of a single toxin
Give 2 examples of toxoid vaccines
- Tetanus vaccine
- Diphtheria vaccine
What is an inactivated vaccine?
Use of killed organisms to stimulate production of antibodies
Give 2 examples of inactivated vaccines
- Typhoid vaccine
- Influenza vaccine
What is an attenuated live vaccine?
- Use of living organisms with reduced virulence (attenuated) but still immunogenic
- Multiply in the body and mimic natural infection with antibody production but without symptoms
Give 2 examples of attenuated live vaccines
- MMR vaccine
- Yellow fever vaccine
What are some safety problems that may arise when preparing a vaccine? (4)
- Contamination
- Inadequate inactivation of killed vaccine.
- Reversion to virulence of attenuated vaccine
- Residual toxicity of toxoids
Which antibody is predominately produced from the 1st injection of an inactivated or toxoid vaccine?
(Primary response)
IgM antibody
Which antibody production increases during a secondary response?
IgG antibody
Some toxoids & inactivated vaccines contain adjuvants, what are these?
Substances which enhance the antibody response
Give 2 examples of adjuvants
- Aluminium phosphate
- Aluminium hydroxide
Vaccine uptake rate must exceed what % for herd immunity to operate well
90%
What are 2 main problems associated with immunisation in first few months of life?
- Infant immune system is not fully developed at birth and capacity to make antibody is limited
- Trans placental maternal antibody may prevent a response to live virus vaccines and reduce that to some killed vaccines.
What may be a benefit of combined vaccines?
May enhance antibody production
What is the time frame between administering two separate live vaccines?
3 weeks apart
Which vaccine uses the mouth as a route of administration?
How does this work?
- Oral polio vaccine (OPV)
- Enables virus to colonise gut and promote both local and humoral antibodies
Majority of vaccines are administered how?
What are the preferred sites?
- Subcutaneous and intramuscular injection
- Anterolateral aspect of thigh
- Upper arm
What is the route of administration of the BCG vaccine?
Intradermal injection
What may be some side effects of some vaccines?
- Pain
- Erythema (reddening)
- Fever
- Malaise
What is a rare side effect of a vaccine?
Anaphylactic reactions
When may you not administer a vaccine to someone? (5)
- If previous severe reaction to that vaccine
- If patient has acute illness
- No live vaccine to immunocompromised patients
- No live vaccine to pregnant women
- No BCG vaccine to HIV +ve or AIDS
