COVID 19

Question 1

what is a coronavirus

Answer 1

• large family of enveloped viruses
• single stranded RNA genome
• S proteins protrude from the viral surface resembling a crown

Question 2

which types of diseases are caused by coronaviruses

Answer 2

• common cold
• severe acute respiratory syndrome (SARS)
• middle east respiratory syndrome (MERS)

Question 3

transmission

Answer 3

• contact with respiratory droplets (most)
• airborne transmission via droplet nuclei (less comon)
• fomites contaminated with respiratory droplets

Question 4

population at risk

Answer 4

• 65+
• individuals with an undelrying medical condition such as diabetes, chronic kidney disease…

Question 5

structure

Answer 5

single stranded (+) genome
enveloped

Question 6

S protein

Answer 6

• Tropism for ACE-2 expressing cells
• S-proteins binding to ACE2 triggers either viral endocytosis, or membrane fusion and viral genome entry
• S protien is coated in glycans which disguise it from the immune system

Question 7

SARS CoV-2 entry

Answer 7

1. receptor binding (S protein to ACE-2 receptor)
2. fusion of virus and host cell membranes and entry

Question 8

hypoxemia

Answer 8

low oxygen in the blood

Question 9

stage 1 - asympotomatic state

Answer 9

• incubation time - 2-14 days
• virus shed by the host in droplets
• virus propagates, mild innate immune response initiated

Question 10

stage 2 - upper airway and conducting airway response

Answer 10

• robust immune response
• clinical manifestations of disease appear on avg 5 days post-exposure
• up to 80% of COVID-19 cases with be either asymptomatic or will arrest as this stage

Question 11

signs and symptoms

Answer 11

• cough
• fever
• shortness of breath
• chills
• muscle pain
• loss of taste and/or smell
• sore throat
• nausea
• diarrhea

Question 11

stage 3 - hypoxia, progression to acute respiraotry distress syndrome within 8-12 days

Answer 11

• critical care/hospitalization necessary
• leading cause of death is hypoxic respiratory failitre complicated by acute respiratory distress syndrome (ARDS)

Question 12

RT-PCR test

Answer 12

molecular test
* advantages : accurate if sample is taken approx. 5 days post-exposure
* disadvanges: may not catch early infections, takes 24-48 hours for results

Question 13

antigen rapid test

Answer 13

imunological test
* advantages: results in ~15 minuts
* disadvantages: not as sensitive as PCR test –> can result in false negatives

Question 14

goal of COVID-19 vaccines

Answer 14

induce production of antibodies that bind to the virus, effectively blocking entry into the host cell to the S protien is the antigen used in most vaccine cadidiates

Question 15

remdesivir

Answer 15

• antiviral
• nucleoside analog that targets the RNA-dependent RNA-polymerase
• inhibit viral replication by terminating RNA transcription prematruely

Question 16

paxlovid

Answer 16

• antiviral
• protease inhibit of the SARS CoV2’s main protease enzyme
• without its protease, SARS CoV2 is unable to cleave viral polyproteins precursors into proteins, and this prevents viral replication

Question 17

bebtelovimab

Answer 17

• IgG antibody that binds the spike protein on SARS CoV2
• blocks attachment to human ACE2 receptor

Question 18

dexamethasone

Answer 18

• anti-inflammatory
• steroid
• relieves inflammation
• recommonded only in hospitlized and severe cases if remdesivir cannot be obtained