vaccines lecture 1 Flashcards
what are the 2 major parts of immune system
- innate
- adaptive
what is the innate immune system
First line of defense
- Responds quickly to invaders
- Primed and ready to fight at all times
- No adaptation in response (same response on re-exposure)
- Acts to confine invader and stops spread
- No memory persists afterwards
what is the adaptive immune system
Second line of defense
- Slower response
- Adapts to invaders (faster and stronger response on re-exposure)
- Memory persists afterwards
The innate immune system has 3 main part what are they
- physical barriers
- chemical barriers
- cellular barriers
The adaptive immune system has 2 main part what are they
- B cells
- T cells
what are the types of immunity
- Passive
- active
what is passive immunity
- can be natural or artificial
- natural: Antibodies transmitted from mother to baby
- artificial: Antibodies acquired from a medicine
what is active immunity
- can be natural or artificial
- natural: Antibodies developed in response to an infection
- artificial: Antibodies developed in response to a vaccination
what is an antigen
Antigen = molecular structure which may be present on the outside surface of a pathogen that triggers response an immune.
What is an antibody
Antibody = proteins produced by B cells. They are specialised Y-shaped proteins that tag antigens for destruction
what is a vaccine
Vaccination = when a vaccine has been administered to you
what is immunisation
Immunisation = process of what happens in your body after you have received a vaccine
Give an example of a pathogen
SARS-CoV-2 ( Covid-19 )
Describe the structure of the SARS-CoV-2 ( Covid-19 ) pathogen
SPIKE PROTEINS
- The spike proteins are anchored into the viral envelope and form a crown like appearance. The spike proteins attach to the target cell and allow the virus to enter it
ENVELOPE
- The RNA is surrounded by an envelope which has different roles in the life cycle of the virus. These may include the assembly of the new virus and helping the new virus to leave the infected cell
RNA
- The RNA is inside the envelope and acts as a template so that once it is inside the host cell, the coronavirus can replicate itself and be released into the body
what is the R₀ value
- Term that describes how contagious/transmissible
an infection disease is - R0=Basic Reproduction Number
- Average number of secondary cases arising from a
primary infection case in an entirely susceptible population - R₀ < 1
- R₀ = 1
-R₀ >1
what is herd immunity
Refers to indirect protection of a community of people from a disease by immunising a critical proportion of that population
What is a vaccine?
- A vaccine is a biological preparation
- Typically contains weakened or inactive parts of a particular disease-causing pathogen
what do vaccines do
- Improves immunity to a particular disease
- Triggers an immune response within the body
- Relies on the generation of immunological memory
- Mimics a natural infection without causing illness to the individual
- Protects not only the vaccinated individual but also their community
how do vaccines work
Vaccination ‘programs’ the immune system to remember a particular disease pathogen by allowing it to ‘practice’ on a weakened or killed version of the pathogen. This is called primary response to a pathogen
If the pathogen invades the body again in full strength, the immune system is ready to respond quickly. This is called a secondary response to a pathogen. Secondary responses happen faster and at a greater magnitude than primary responses, resulting in the creation of more antibodies to fight the pathogen and more memory cells to fight it in the future
