COVID-19 Flashcards
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What are the genera within the Coronaviridae family?
(a) Alphacoronavirus
(b) Betacoronavirus
(c) Gammacoronavirus
(d) Deltacoronavirus
List three emergent Coronaviruses and their respective genera.
👑 MERS-CoV (Middle East Respiratory Syndrome Coronavirus): betacoronavirus
👑 SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus): betacoronavirus
👑 SARS-CoV-2: betacoronavirus
SARS-CoV-2
(a) Order
(b) Family
(c) Genus
(d) Sub-genus
(a) Order: Nidovirales
(b) Family: Coronaviridae
(c) Genus: Betacoronavirus
(d) Sub-genus: Sarbecovirus
List four common Coronaviruses and their respective genera.
👑 Human coronavirus 229E (alphacoronavirus)
👑 Human coronavirus NL63 (alphacoronavirus)
👑 Betacoronavirus 1 (OC43) (betacoronavirus)
👑 Human coronavirus HKU1 (betacoronavirus)
Briefly discuss the structure of Coronaviruses [including the various protein components].
🛸 enveloped
🛸 Spike (S) proteins protrude form the viral envelope and are responsible for binding to host cell receptors.
🛸 Envelope (E) proteins embedded in the envelope are small proteins involved in virus assembly and release.
🛸 Membrane (M) proteins are the most abundant structural proteins, giving the virus its shape.
🛸 Nucleocapsid (N) proteins bind to the RNA genome, forming a helical structure.
[Diagram 1] [Diagram 2] [Diagram 3]
[Image 1] [Image 2] [Image 3]
What type of genome do Coronaviruses have?
single strand, positive-sense RNA
What is the primary receptor for SARS-CoV-2?
ACE2 (angiotensin-converting enzyme 2) receptor
Briefly discuss SARS-CoV-2 transmission and pathogenesis.
Transmission:
👑 The virus primarily enters the body through respiratory droplets when an infected person coughs, sneezes, or talks.
Pathogenesis:
👑 The virus begins to replicate in the cells lining the nasopharynx and oropharynx.
👑 This initial replication can cause symptoms like sore throat and nasal congestion.
👑 The virus then spreads down the respiratory tract to the bronchi and eventually to the lungs.
👑 This can lead to more severe respiratory symptoms such as cough and shortness of breath.
👑 In the lungs, the virus specifically targets type 2 pneumocytes, which are cells responsible for producing surfactant to keep the alveoli (air sacs) open. The destruction of these cells impairs gas exchange and leads to respiratory distress.
👑 The immune response to the infection causes inflammation in the lung tissue.
👑 Inflammatory processes increase vascular permeability, leading to fluid leakage into the alveoli.
👑 Chronic inflammation can result in fibrosis (scarring) of lung tissue, further impairing lung function.
👑 The damage to the alveoli and fluid accumulation reduce the lungs’ ability to oxygenate the blood, leading to hypoxia (low blood oxygen levels).
👑 This can cause symptoms such as cyanosis (bluish discoloration of the skin), confusion, and fatigue.
👑 The virus and the immune response can damage both the epithelial cells lining the airways and the endothelial cells lining the blood vessels.
👑 This damage can lead to further leakage of fluid and proteins into the lung tissue.
👑 In severe cases, the immune response can become dysregulated, leading to a massive release of cytokines (cytokine storm).
👑 This can cause widespread inflammation, leading to septic shock, characterized by dangerously low blood pressure and organ failure.
Briefly outline signs and symptoms of SARS-CoV-2 infection, categorizing them into common, less common and emergency signs.
(a) Common signs
fever, cough, fatigue
(b) Less common
chills, sorethroat, headache, muscle aches, diarrhoea, nausea/vomiting, runny nose, loss of smell, loss/change in taste
(c) Emergency signs
difficulty in breathing, persistent chest pain, confusion, cyanosis, loss of consciousness
List risk factors for severe Covid-19.
Age > 60, Coronary Artery Disease, Stroke, Diabetes, Hypertension, Cancer, Chronic Lung Disease, Frailty, Pregnancy, Immunosuppression, Chronic Kidney Disease, Obesity
Briefly discuss the stages of Covid-19.
(1) Incubation Period
Duration: Typically 2-14 days after exposure, with an average of 5-6 days.
(2) Early Stage (Days 1-7)
Initial symptoms often include fever, dry cough, fatigue, sore throat, and muscle aches. Some people may experience loss of taste or smell, nasal congestion, or gastrointestinal symptoms like diarrhea.
(3) Pulmonary Stage (Days 7-12)
Symptoms can worsen, leading to difficulty breathing (dyspnea), persistent chest pain, and increased cough. Some patients may develop pneumonia.
(4) Hyperinflammatory Stage (Days 10-14)
The immune system’s overreaction can cause a cytokine storm, leading to widespread inflammation and multi-organ damage.
This stage can result in septic shock, organ failure, and increased risk of death.
(a) What is long COVID?
(b) List common symptoms of long COVID.
[Hint: general, respiratory/heart, neurological, digestive]
(a) This is a condition where symptoms last for at least three months after the initial COVID-19 infection.
(b) Symptoms:
General: fatigue, fever, headaches
Respiratory/Heart: difficulty breathing, cough, chest pain, heart palpitations
Neurological symptoms: brain fog, sleep problems, dizziness, changes in smell/taste
Digestive: diarrhea, stomach pain
Briefly discuss sample collection and testing methods for diagnosis of COVID-19.
Sample collection: a nasopharyngeal or oropharyngeal swab is taken
Testing methods:
(1) PCR
(2) Rapid tests for antigens
(3) Sequencing
(4) Imaging: a chest X-ray may be done to show lung abnormalities such as infiltrates or consolidation.
Briefly discuss supportive treatment measures of COVID-19.
👑 Antipyretics/Analgesics: Used to reduce fever and relieve pain.
👑 Oxygen Therapy: Administered to patients with low oxygen levels to maintain adequate oxygenation.
👑 Anticoagulation Therapy: Given to hospitalized patients to prevent blood clots.
👑 Immunomodulation: Includes the use of steroids (e.g., dexamethasone) and anti-IL6 agents (e.g., tocilizumab) to modulate the immune response.
👑 Monoclonal Antibodies: Target the SARS-CoV-2 virus to neutralize it and prevent severe disease progression.
👑 Fluid/Electrolyte Therapy and Renal Care: Ensures proper hydration and kidney function.
👑 Antibiotics: Used when bacterial superinfection is suspected.
👑 Mechanical Ventilation: For patients with severe respiratory failure.
👑 ECMO (Extra-corporeal Membrane Oxygenation): Used in critical cases to provide cardiac and respiratory support.
List three immunomodulants that may be administered to patients suffering from COVID-19.
💊 Dexamethasone
💊 Anti-IL6 Receptor (Tocilizumab) – for critical cases
💊 Janus-Kinase Inhibitor (Baricitinib)
Further notes:
Dexamethasone is a corticosteroid used to reduce inflammation and suppress the immune response.
Barcitinib modulates the immune response by inhibiting the signaling pathways of various cytokines.
List two RNA polymerase inhibitors that may be administered to patients suffering from COVID-19.
Name one protease inhibitor [blocks activity of viral proteases] that may be administered to patients suffering from COVID-19.
Paxlovid (Nirmatrelvir + Ritonavir)
Further notes:
🧬 If you’re desperate:For there to be pax (peace) in Nirvana, no teasing (protease) rituals are allowed.
🧬 Ritonavir, originally developed as a HIV protease inhibitor, is primarily used to boost the effectiveness of other protease inhibitors. It works by inhibiting the enzymes that break down these drugs, allowing them to remain active in the body for a longer period.
🧬 Nirmatrelvir targets the SARS-CoV-2 3CL protease, an enzyme crucial for the virus to replicate its genetic material.
List some monoclonal antibodies that may be used for early treatment and pre-exposure prophylaxis of COVID-19.
💉 Tixagevimab + Cilgavimab
💉 Sotrovimab
💉 Bamlanivimab + Etesevimab
💉 Casirivimab + Imdevimab
Outline prevention measures against COVID-19.
💉 Vaccination
💉 Screening at ports of entry
💉 Contact tracing
💉 Travel restriction
💉 Masks
💉 Physical distancing
◾ Isolation of sick persons
◾ Quarantine (self, supervised, contacts)
◾ Closure of schools, pubs, restaurants
◾ Working from home
Briefly discuss vaccination strategies against COVID-19.
(1) mRNA Vaccines: These vaccines use messenger RNA to instruct cells to produce a protein that triggers an immune response. Examples include the Pfizer-BioNTech and Moderna vaccines.
(2) Viral-vector Vaccines: These vaccines use a modified virus (not the coronavirus) to deliver genetic material that instructs cells to produce a protein that triggers an immune response. Examples include the AstraZeneca and Johnson & Johnson vaccines.
(3) Inactivated Vaccines: These vaccines use a virus that has been killed or inactivated so it cannot cause disease but still triggers an immune response. Examples include the Sinopharm and Sinovac vaccines.
(4) Subunit Vaccines: These vaccines use pieces of the virus (often proteins) to trigger an immune response without using the whole virus. An example is the Novavax vaccine.
Further notes:
mRNA Vaccine
🧬 COVID-19 mRNA vaccines contain mRNA that encodes the spike protein found on the surface of the SARS-CoV-2 virus.
🧬 When the vaccine is injected into the upper arm, the mRNA enters cells near the injection site.
🧬 Inside the cells, the mRNA provides instructions to produce the spike protein. This protein is harmless on its own but is recognized by the immune system as foreign.
🧬 The immune system responds by producing antibodies and activating T-cells to fight the spike protein. This process trains the immune system to recognize and combat the actual virus if the person is exposed in the future.
List four challenges facing vaccination against COVID-19.
💉 Supply (Inequality); limited production and unequal distribution
💉 Distribution; logistical challenges
💉 Misinformation
💉 Vaccine hesitancy
One of the following is recommended for treatment of COVID-19?
(a) Acyclovir
(b) Remdesivir
(c) Lamivudine
(d) Ribavirin
(e) Hydroxychloroquine
(b) Remdesivir
Which one of the following is recommended for treatment of COVID-19?
(a) Favipravir
(b) Nirmatrelvir
(c) Ribavirin
(d) Acyclovir
(e) Azithromycin
(b) Nirmatrelvir
