Immunisation Flashcards
Which substance give passive natural immunity to child via placenta
IgG
Why is artificial immunity given by pooling many peoples igG to infants
They get hypogammaglobulinemia at a young age
Other than IV igG what other passive artificial immunity is there
Tetanus antitoxin
Why is secondary response always better
Larger amount of memory cells = more clonal expansion and more antibodies and also they undergo more shm
Why does measles need more immunisation to reach herd immunity
Need higher % because it is more contagious than others. Diff diseases have different percentage herd
What are the 5 vaccine types
Inactivated dead
Live attenuated
Subunit
Toxoid (diphtheria or tetanus)
Conjugate
Give an example of dead vaccine
Salk polio vaccine
What needs to be alive for dead vaccines to work
Antigens
Why are aceullsr vaccines better than cellular dead eg whooping cough
Less side effects
What is live attenuated
Either chemically treated or a homologous less virulent pathogen given
What is injected instead of tuberculosis mycobacterium in live attenuated
Bcg bovis strain of mycobacterium
Why is live attention advantageous
Only need 1 dose because highly antigenic
Usually gives right type of response
What is the issues with live attenuated
Risk of reversion to virulence
Risk of inactivation
Contamination risk
Disease cause in immunocompromised
What type of virus is polio and how does it infect
Entero virus via oral faecal route
Usually polio causes subclinical symptoms of a cold. What happens in 0.5% of people
Infects the cns and causes paralysis
Which country was cleared of polio via vaccines
India
Which countries still have an issue with polio
Afghanistan and Pakistan
What are subunit vaccines and give example
Isolated antigens given
Eg pneumovax for strep has 23 polysaccharides
What is the risk with subunit vaccines
Could get non responders
What is the biggest example of conjugate vaccines for young kids
Prevnar 13, adds diphtheria to strep polysaccharides to cause a TD ag response
What is reverse vaccinology
Genome screening of pathogens to identify possible proteins to use in vaccines
How was reverse vaccinology done for neisseria meningitis
600 genes identified as potential
28 surface proteins produced ab responses in mice
4 were put into a vaccine
What is the importance of the right response eg CD8 for hiv
If not the infection isn’t fought off, and can cause immunopathology eg respiratory syncytial virus vaccine caused 2 deaths
What are adjuvants
Substances administered with ag in vaccines to enhance immune response
What is it called when adjuvants enhance immune response
Immunostimulatory
Adjuvants are depot. What does this mean
Hold ag longer under the epidermis for dendrites signal
How do adjuvants affect dendrites
Activate via tlr
Cause danger signal
Increase ag uptake by dendrites
Stimulate chemokine release for dendrites to go to slt
How are adjuvants good at stimulating CD8
Cause dendritic cross presentation on MHC I
What are the 2 adjuvants given to animals
Freunds- oil in water emulsion (oil is stimulatory)
Freunds Complete adjuvant - with mycobacterium inside
What adjuvants are used in humans
Alum based
Aluminium hydroxide or phosphate
What response do alum adjuvants have in humans
Better antibody responses
Give examples of newer adjuvants
Ones with squalene based oil in water emulsion
Some with vitamin e increased immune response
Some with lps derivative to enhance tlr activation
What is the az covid vaccine an example of
Live attenuated
Inject adenovirus
