Covid 19 (Sars Cov 2)

Question 1

Structure Covid-19

Answer 1

Large
enveloped
pleomorphic

Question 2

Genetic material

Answer 2

ssRNA (+ve)

Question 3

Surface antigen covid 19

Answer 3

Spike glycoprotein (required for entry)

Question 4

Proteins covid 19

Answer 4

Spike glycoprotein
Membrane protein
Envelope protein
(lipid bilayer)

Question 5

Development of SARS

Answer 5

Sars Cov 1
Mers
Sars Cov 2

Question 6

Sars Cov 1&2 bind to

Answer 6

ACE2 protein

Question 7

Mers binds to

Answer 7

DDP4

Question 8

Sars Cov 1

Answer 8

Asia 2002

Bats –> civets –> humans

Question 9

MERS

Answer 9

Middle east 2012

Bats –> camels –> humans

Question 10

Sars Cov 2

Answer 10

Wuhan, China 2019

Bats via unknown

Question 11

All Coronaviruses came from…

Answer 11

BATS

Question 12

Transmission Covid

Answer 12

Airborne (suspended, remain for a while)

droplets (coughs and sneezes create droplets of saliva and mucus)

Question 13

Droplet vs airborne sizes

Answer 13

Droplets >5 microns

Airborne <5 microns

Question 14

Barriers to Coronavirus

Answer 14

Mucus traps virus particles
Ciliated respiratory epithelium
Lungs: IgA, natural killer and macrophages

Question 15

How does virus enter cells?

Answer 15

Spike protein binds to ACE2 membrane (lungs, GI, heart and kidneys)
Receptor mediated endocytosis (cell envaginates around virus)

Question 16

How does coronavirus replicate?

Answer 16

ssRNA +ve –> ssRNA -ve –> ssRNA +ve
(RNA dependent RNA polymerase)
ssRNA +ve + viral proteins = nucleocapsid

(viral proteins come from ssRNA +ve)

Question 17

Enzyme involved in coronavirus replication

Answer 17

RNA dependent RNA polymerase (RdRp)

Question 18

Incubation period omicron

Answer 18

3 days

Question 19

Top 5 symptoms of omicron

Answer 19

Runny nose
Headache
Fatigue
Sneezing
Sore throat

Question 20

Diagnosis of COVID 19 methods

Answer 20

RT-qPCR

Lateral flow test

Question 21

RT-qPCR stands for…

Answer 21

Reverse transcriptase quantitative PCR

Nasopharyngeal swap

Question 22

Method of RT-qPCR

Answer 22

Swab
Extract RNA and convert to DNA
Amplify via PCR with SARS-COV2 primers
Viral RNA presence = active infection

Question 23

Requirements to convert covid RNA to DNA and amplify

Answer 23

Reverse transcriptase
Sequence specific primers
DNA polymerase
dNTP (deoxyribonucleotide triphosphate)
mRNA

Question 24

Lateral flow explained

Answer 24

Antibodies on lateral flow
Antigens on virus bind to antibodies
Antibodies dragged up test line by antigens
Antibodies bind to 2nd antibody to give visual result

Question 25

LFT vs PCR

Answer 25

LFT less sensitive but very specific (antibody are specific) LFT shows +ve when infectious (tests for surface proteins) PCR tests for genetic material - can remain for weeks/months after

Question 26

Why do we get variants of coronavirus?

Answer 26

``` Constantly replicating (10 hour life cycle) RNA polymerase: high error rate and lack of proofreading = mutations (genetic variation/resistance) ```

Question 27

Different covid variants

Answer 27

``` Alpha (May, UK) Beta (August, south africa) Gamma (November, Brazil) Delta (October, India) Omicron (November, everywhere) ```

Question 28

Early variants

Answer 28

Spread more easily Vaccines less effective (B-D) BUT effective protection against severe disease

Question 29

Different vaccines

Answer 29

Viral vector RNA Whole virus Protein subunit

Question 30

Viral vector vaccine

Answer 30

Harmless virus used Alter virus to contain some COVID genetic code (Oxford/Astrazeneca)

Question 31

RNA vaccine

Answer 31

Synthetic version of COVID 19 genetic code (mRNA) | Pfizer/Moderna

Question 32

Whole virus vaccine

Answer 32

Weakened/inactive virus | CoronaVac

Question 33

Protein subunit vaccine

Answer 33

Pieces of Covid 19 virus eg spike protein fragments (Novavax)

Question 34

What do whole virus/protein subunit vaccines create?

Answer 34

Immune response

Question 35

What do viral vector/RNA vaccines create?

Answer 35

Genetic code tells our cells to make spike protein which then triggers immune response