L1 Covid Vaccines Flashcards
What are coronaviruses?
Diverse family of enveloped positive-sense single-stranded RNA viruses
What is the biology and pathogenesis of SARS-Cov2 similar to?
SARS & MERS
What was covid 19 caused by?
SARS-Cov2
When can viruses replicate?
Within human cells
What does the spike protein allow for?
essential for attachment & entry
What receptor does the virus’ spike protein lock on to?
ACE2
When is the virus hidden from the immune system?
Within the cell
What cells engulf the virus?
APC
What is the B cell response?
Development of antibodies
What immune cells destroy virus-infected cells?
T cells
What response do you get in natural infection?
Secretory IgA response in nasal cavity
IgG1 (circulatory) in lungs
What response was the intradermal vaccination good at developing?
IgG response
not good at slgA1 response as nasal never exposed to antigen
What is the downside of the intranasal vaccine?
Does not translate to other regions
What is a real difficulty for vaccines?
Stopping transmission
What are 4 protein vaccine targets?
Spike proteins
membrane
envelope
nucleocapsid
Why did they not look at other proteins after the spike protein?
Poor immunogenicity from M+E proteins
N protein vaccination caused serious issues (inappropriate immune response)
What are 4 challenges with vaccine development?
Around for a long time as transient infections
Mutate and evolve in real time
How quickly can you implement global vaccination program?
How can you regulate a vaccine in an emergency situation?
Why did normal processes change for covid vaccine?
Political pressure on regulatory system
What was changed in the vaccine development by FDA?
Didn’t have to finish phase I before phase II - allowed for overlap - reduced 15 yr process
Why was there a large variety of different types of vaccines?
- each company had their own vaccine platforms
What are 2 main aims of vaccine?
Elicit immune response
reduce symptoms
What is RBD?
Receptor binding domain
What are 6 examples of vaccines?
RBD of spike protein
Recombinant spike-protein-based vaccines
VLPs
Replication incompetent/competent
Nuclei acid based
inactivated virus vector
What type of vaccine dominate?
RNA vaccines - easy to manufacture as they are non-protein based
What is an example of a non-replicating viral vector?
Adenovirus eg. Astrazeneca
What are characteristics of the AstraZeneca vaccine?
single dose
66% protection
good results overall
What are characteristics of Pfizer vaccine?
2 dose
-70 storage
95% effective
mostly used in ireland
What are characteristics of Novavax?
2 dose
recombinant spike-protein-based
Matrix-M adjuvant
90% effective
How did new variants compare to original stain?
New variants were more transmissible but less pathogenic
What is a pan vaccine?
Vaccine effective against all coronavirus variants and previous strains
What were ethical considerations?
Supply and demand
vaccine equity
equitable distribution
vaccine hesitancy
How many doses were needed?
16bn doses
Were vaccines rolled out evenly on a global scale?
no
What were the top 4 countries with vaccination rate in Europe?
Malta
Denmark
Italy
Ireland
What is a serious implication of vaccine hesitancy?
Health services as non-vaccinated individuals most more likely to take up ICU spaces
What variant showed waning immunity?
Delta variant
Why weren’t children vaccinated?
didn’t develop serious disease - problem if there is an outbreak with a new variant
What are therapeutics?
classical anti-viral drugs targeting RNA dependent RNA polymerase or protease
Whats an example of therapeutics?
Mpro inhibitors (Remdesivir)
RdRp inhibitors (Paxlovid)
