Immunity to COVID 19

Question 1

what is the structure of COVID19

Answer 1

positive strand RNA virus
spike glycoprotein
envelope

Question 2

where did the delta variant originate from

Answer 2

india 2021

Question 3

where did the gamma variant originate from

Answer 3

brazil 2021

Question 4

where did the alpha variant originate from

Answer 4

UK 2020

Question 5

where did the omicron variant originate from

Answer 5

south africa

Question 6

what change does N501Y denote

Answer 6

asparagine to tyrosine at position 501 of spike protein

Question 7

what differences does the omicron varient have

Answer 7

less efficient at replicating in lung epithelia
lower levels in LRT
shorter incubation period
less hospitalisations

Question 8

how do variants emerge

Answer 8

natural selection and persistent infection

Question 9

what is the closest relative to SARSCOV2

Answer 9

RaTG13 96% in bats

Question 10

what fuses virus with host cell membrane

Answer 10

TMPRSS2 and FURIN

omicron doesnt bind well

Question 11

how does the innate system respond to covid

Answer 11

TLR7/8 senses ssRNA
TLR3 senses dsRNA intermediates
RIG1/MDA5 - cytoplasmic viral RNA
inflammasome activated
cytokines and interferons produced

Question 12

what transcription factors cause production of cytokines and interferons

Answer 12

NFKB, IRF3, IRF7

Question 13

what is a prominant immune feature of COVID19

Answer 13

impaired interferon response - antagonistic mechanisms agaist IFN signalling

Question 14

how does severe infection with SARS-CoV-2 effect B cell response

Answer 14

induces a robust extrafollicular

response but an impaired germinal centre (GC) B cell response in some individuals

Question 15

how do COVID19 variants effect t cell immune response

Answer 15

they do not - recognise conserved peptides on spike protein

Question 16

Characteristics of Immune Response in severe COVID-19 patients

Answer 16

Acute Respiratory Distress Syndrome (ARDS)
increased IL-6, IL-8, TNFα and IP10 (chemokine)
cytokine storm
immature neutrophils
exhausted NK and DC
t cell lymphopenia

Question 17

what do excessive amounts of pro inflammatory molecules do

Answer 17

promote vascular permeability and organ damage, hypercaogulation

Question 18

lab tests that indicate severe infection

Answer 18

high IL6, IL8, TNFa, IP10
high CRP
high D dimer
high neutrophils
low lymphocytes

Question 19

Immunomodulatory Treatment Options

Answer 19

Monoclonal Antibody drugs can block the effect of
cytokines such as IL-6, IL-8, TNFα
Glucocorticoids (Dexamethasone & Prednisolene) are powerful, broad-active
immunosuppressive drugs - NF-kB

Question 20

what is Merck

Answer 20

RNA dependent RNA polymerase inhibitor

Question 21

what is Paxlovid

Answer 21

SARS COV 2 protease inhibitor

Question 22

what type of vaccines are moderna and pfizer

Answer 22

DNA and RNA

Question 23

what type of vaccine is novavax

Answer 23

subunit

Question 24

what type of vaccine is astrazenaca and janssen

Answer 24

viral vector

Question 25

how do some vaccines change spike protein

Answer 25

keep it in prefusion standing up conformation

Question 26

features of mRNA vaccine design

Answer 26

Nucleotide modification: substitution of Uridine for Pseudouridine- Protects the mRNA from nuclease degradation
Use of preferred codons for translation in human cells

Question 27

what protects mRNA to deliver it through PM

Answer 27

lipid nano particles