CS2 - Dengue Part 2 Flashcards
How should dengue without warning signs (Group A) be treated in an outpatient setting?
Treatment focuses on supportive care and preventing complications such as dehydration:
Prevent dehydration:
Administer oral rehydration solution to maintain hydration.
Ensure fluids are maintained.
Fever control:
Paracetamol (acetaminophen) should be given every 6 hours to control fever and pain.
Avoid NSAIDs (Nonsteroidal Anti-Inflammatory Drugs), as they can increase the risk of bleeding.
Use a tepid sponge to help reduce fever.
What observations should be made for patients with dengue without warning signs?
Close monitoring is essential to identify any worsening condition. Look out for:
Warning signs such as signs of dehydration, bleeding, or organ dysfunction.
No improvement in symptoms after treatment.
Deterioration during defervescence (cooling down of the fever).
No urination for more than 4-6 hours, which could indicate dehydration or renal issues.
When should dengue without warning signs (Group A) be hospitalized?
Hospitalization is required if the patient shows any signs of:
Warning signs or worsening condition.
No improvement or deterioration in symptoms.
Failure to urinate for 4-6 hours, suggesting severe dehydration.
What is the general approach for dengue recovery in Group A patients?
Recovery involves:
Supportive care with hydration and fever control.
Observation for warning signs and any signs of deterioration.
Ensuring the patient remains well-hydrated and monitoring vital signs regularly.
How do NSAIDs work at the biochemical level?
NSAIDs primarily inhibit the enzymes cyclooxygenase (COX), leading to the disruption of the arachidonic acid pathway. This results in the decreased production of prostaglandins (PGs) and leukotrienes (LTs).
Cyclooxygenase (COX): COX is responsible for converting arachidonic acid to prostaglandins (PGs) like PGI2 (prostacyclin), TXA2 (thromboxane A2), and PGE2, which play crucial roles in vasodilation, platelet aggregation, and inflammation.
Lipoxygenase: Also acts on arachidonic acid to produce leukotrienes (LTs) such as LTB4, LTC4, LTD4, and LTE4, which mediate chemotaxis, bronchospasm, and vascular permeability.
What are the effects of prostaglandins (PGs) in the body?
Prostaglandins have multiple roles depending on the type:
PGI2 (prostacyclin): Causes vasodilation and decreases platelet aggregation.
TXA2 (thromboxane A2): Induces vasoconstriction and increases platelet aggregation.
PGE2: Involved in vascular permeability and fever.
How do leukotrienes (LTs) affect the body?
Leukotrienes are involved in inflammation and immune response:
LTB4: Plays a role in chemotaxis, attracting immune cells to sites of infection or injury.
LTC4, LTD4, LTE4: Cause bronchospasm and increase vascular permeability, leading to inflammation and tissue swelling.
What is the role of NSAIDs in inflammation and pain?
NSAIDs reduce inflammation and pain by inhibiting the cyclooxygenase (COX) enzymes, thereby:
Decreasing prostaglandin (PG) production.
Reducing vasodilation, vascular permeability, and platelet aggregation.
Limiting chemotaxis and bronchospasm in response to inflammatory stimuli.
Why are NSAIDs avoided in some conditions like dengue fever?
NSAIDs are avoided in certain viral infections like dengue fever due to their potential to:
Increase the risk of bleeding by inhibiting platelet aggregation.
Cause gastric irritation or damage, leading to bleeding.
Aggravate renal issues in some cases.
What are the main types of cyclooxygenase (COX) enzymes?
There are two main types of COX enzymes:
COX-1: Constitutive enzyme involved in normal physiological processes like gastric protection, vascular homeostasis, platelet aggregation, renal function, and reproductive functions.
COX-2: Inducible enzyme primarily expressed at the site of inflammation, contributing to pain, fever, and swelling during inflammatory responses.
What are the functions of COX-1?
COX-1 is involved in:
Gastric protection: Helps maintain the integrity of the stomach lining.
Vascular homeostasis: Regulates blood vessel tone.
Platelet aggregation: Plays a role in blood clotting.
Renal function: Helps in kidney function and fluid balance.
Reproductive functions: Involved in processes like labor and pregnancy.
Where is COX-2 primarily expressed, and what is its role?
COX-2 is primarily expressed at the site of inflammation and is involved in:
Pain and swelling during inflammatory responses.
Fever production during immune activation.
Induction of prostaglandins that mediate inflammation and tissue damage.
How do NSAIDs affect COX-1 and COX-2?
NSAIDs inhibit both COX-1 and COX-2 enzymes, though some NSAIDs are selective for COX-2 inhibition:
Non-selective NSAIDs inhibit both COX-1 and COX-2, reducing inflammation, pain, and fever but also potentially causing gastric irritation, ulceration, and bleeding due to the inhibition of COX-1.
COX-2-selective NSAIDs mainly inhibit COX-2, reducing inflammation and pain with less effect on COX-1, thus sparing some of the protective functions like gastric protection.
Why is COX-1 inhibition a concern in certain treatments?
nhibiting COX-1 can lead to several adverse effects, such as:
Gastric irritation or ulceration because COX-1 is involved in maintaining the stomach lining.
Bleeding risks, as COX-1 plays a role in platelet aggregation.
Potential renal dysfunction as COX-1 helps in regulating kidney function.
What role does COX-1 play in vascular homeostasis?
COX-1 helps in the regulation of vascular homeostasis, meaning it contributes to the balance of blood vessel tone, supporting appropriate blood flow and blood pressure regulation.
What is the treatment approach for Dengue with warning signs (Group B)?
The treatment approach for Dengue with warning signs (Group B) involves inpatient care with:
Fluid monitoring: Track intake and output of fluids.
Laboratory tests: Regular Full blood count (FBC) to monitor blood cell levels.
Vital signs monitoring: Measure vital signs every 4 hours.
Adequate fluid intake: Ensure the patient maintains proper fluid intake.
IV isotonic crystalloid solution: Administer if fluid intake is inadequate.
What is the role of fluid monitoring in the treatment of Dengue with warning signs?
Fluid monitoring is crucial for managing fluid balance, ensuring the patient remains adequately hydrated while avoiding fluid overload. Regular monitoring of intake/output helps assess whether more fluids are needed or if adjustments should be made.
How are IV fluids used in treating Dengue with warning signs?
If fluid intake is inadequate, IV isotonic crystalloid solutions are administered. Fluid reassessment occurs every 2-4 hours, adjusting the fluid intake based on:
Improvement: Continue IV fluids for another 2-4 hours.
No improvement: Increase IV fluids for 1-2 hours.
What action should be taken if the patient’s condition does not improve after fluid reassessment?
If the patient shows no improvement after fluid reassessment, the IV fluids should be increased for 1-2 hours. Regular monitoring should continue to adjust the treatment as needed.
What should be done if compensated or hypotensive shock develops in Dengue with warning signs?
f the patient develops compensated or hypotensive shock, they should be treated according to Group C guidelines, which involve more intensive management, including higher priority fluid resuscitation and other supportive measures.
What is the proportion of extracellular fluid in the body?
Extracellular fluid makes up about 1/3 of the body’s total fluid volume.
What are the components of extracellular fluid?
Extracellular fluid consists of:
25% plasma (the fluid component of blood)
75% interstitial fluid (ISF) (fluid surrounding cells)
What is plasma in the context of extracellular fluid?
Plasma is the fluid portion of blood and accounts for 25% of extracellular fluid. It transports cells, nutrients, waste products, and proteins throughout the body.
What is interstitial fluid (ISF) in the context of extracellular fluid?
interstitial fluid (ISF) is the fluid that surrounds the cells, making up 75% of the extracellular fluid. It acts as the medium for nutrient and waste exchange between blood and cells
How is extracellular fluid controlled within the body?
The control of extracellular fluid involves maintaining balance through fluid movement between plasma (inside blood vessels) and interstitial fluid (in the space between cells). This balance is regulated by factors such as capillary pressure, osmotic gradients, and cell membrane permeability.
What is the relationship between hydrostatic and osmotic pressures at the arterial end of a capillary?
At the arterial end of a capillary, hydrostatic pressure is greater than osmotic pressure, leading to a net flow of fluid out of the capillary into the interstitial space.
What is the relationship between hydrostatic and osmotic pressures at the venous end of a capillary?
At the venous end of a capillary, hydrostatic pressure is less than osmotic pressure, leading to a net flow of fluid into the capillary from the interstitial space.
What is the direction of fluid flow at the arterial end of a capillary?
At the arterial end, the net flow is out, meaning fluid is pushed from the capillary into the surrounding tissue due to high hydrostatic pressure.
What is the direction of fluid flow at the venous end of a capillary?
At the venous end, the net flow is in, meaning fluid is drawn back into the capillary from the interstitial space due to higher osmotic pressure.
What causes the net flow out of fluid at the arterial end of the capillary?
The net flow out at the arterial end is caused by high hydrostatic pressure in the capillary, which forces fluid into the surrounding tissues, despite the osmotic pressure trying to pull fluid back.
: What causes the net flow in of fluid at the venous end of the capillary?
The net flow in at the venous end occurs because osmotic pressure in the capillary exceeds the hydrostatic pressure, drawing fluid back into the capillary.
How does extracellular fluid play a role in fluid balance during dengue?
In dengue, increased capillary permeability leads to fluid leakage from the plasma into the interstitial space, causing fluid loss and contributing to shock if not managed properly.
hat happens to extracellular fluid distribution in severe dengue?
In severe dengue, plasma leakage into the interstitial space causes a reduction in circulating plasma volume, leading to hypovolemic shock and the need for careful fluid management.
Why is fluid management critical in dengue treatment?
Fluid management is essential in dengue because plasma leakage can lead to dehydration, shock, and organ dysfunction, requiring precise fluid resuscitation and monitoring to restore balance.
What occurs at the arterial end of the capillaries in dengue?
At the arterial end of the capillaries in dengue, hydrostatic pressure is higher than osmotic pressure, leading to net fluid outflow into the interstitial space.
What happens at the venous end of the capillaries in dengue?
At the venous end of the capillaries in dengue, osmotic pressure exceeds hydrostatic pressure, leading to a reduced fluid return into the capillaries (less fluid is reabsorbed).
How does capillary exchange change in dengue compared to normal conditions?
n dengue, increased capillary permeability causes fluid leakage into the interstitial space, reducing the return of fluid at the venous end and exacerbating fluid imbalance and hypovolemic shock.
How does hydrostatic pressure affect capillary exchange in dengue?
In dengue, increased hydrostatic pressure at the arterial end pushes more fluid out of the capillaries, contributing to plasma leakage into the interstitial space, worsening fluid loss.
What is the result of impaired fluid reabsorption at the venous end in dengue?
The impaired fluid reabsorption at the venous end due to reduced hydrostatic pressure and increased permeability worsens plasma leakage, leading to hypovolemia and shock.
How is the fluid flow affected in severe dengue?
In severe dengue, the net fluid flow is increased out of capillaries at the arterial end, and the fluid return at the venous end is greatly reduced, causing plasma leakage and contributing to circulatory failure.
What is the primary composition of a crystalloid solution?
A crystalloid solution primarily contains electrolytes dissolved in water, such as saline or Ringer’s solution.
What is the key difference between crystalloids and colloids?
Crystalloids contain electrolytes in water, while colloids contain proteins or polysaccharides (large molecules) that help maintain osmotic pressure.
How do crystalloids affect fluid balance in dengue treatment?
Crystalloids are used to replace lost fluids and maintain hydration, and they can pass through capillary membranes into the interstitial space to balance the fluid loss in dengue.
What is the role of colloid solutions in managing fluid loss in dengue?
Colloid solutions, which contain proteins like albumin, help expand plasma volume by retaining water in the blood vessels and are used to restore plasma during severe dengue or hypovolemic shock.
How do crystalloids differ from colloids in terms of fluid retention?
Crystalloids tend to diffuse easily across capillary membranes, leading to less retention in the vascular space, while colloids contain larger molecules that stay in the vascular compartment, promoting greater fluid retention within the blood vessels.
Why are crystalloids preferred for initial fluid management in dengue?
Crystalloids are preferred for initial fluid replacement because they are easily available, inexpensive, and effective in maintaining hydration in the early stages of dengue.
What is a key characteristic of compensated shock regarding blood pressure (BP)?
n compensated shock, the blood pressure remains normal despite the body’s compensatory mechanisms.
What is commonly observed in terms of heart rate during compensated shock?
Tachycardia (increased heart rate) is a common sign, as the body attempts to maintain perfusion to vital organs.
How does the respiratory rate change during compensated shock?
The respiratory rate increases as the body tries to compensate for oxygen delivery and maintain acid-base balance.
What causes cold, clammy skin in compensated shock?
Peripheral vasoconstriction occurs to preserve blood flow to vital organs, causing the skin to become cold and clammy.
What does a weak peripheral pulse indicate in compensated shock?
A weak peripheral pulse suggests reduced blood flow to the extremities due to compensatory vasoconstriction.
What is the significance of delayed capillary refill in compensated shock?
Delayed capillary refill indicates poor peripheral circulation and inadequate perfusion, often a sign of compensatory shock.
How is urine output affected in compensated shock?
Reduced urine output occurs as the kidneys receive less blood flow due to compensatory mechanisms aiming to preserve vital organ perfusion.
What is the key focus of treatment for dengue with compensated shock (Group C)?
The focus is on fluid monitoring and vital signs monitoring to manage shock and maintain hemodynamic stability.
How frequently should vital signs be monitored in dengue with compensated shock (Group C)?
Vital signs should be monitored every 1-2 hours to assess and manage shock progression.
What is the initial fluid management approach for improved clinical status in dengue with compensated shock?
Fluid reduction to 5-7 ml/kg/hour over 2-4 hours is recommended for further improvement.
What is the next step in fluid management for dengue with compensated shock after further improvement?
Fluid intake should be further reduced to 3-5 ml/kg/hour over 2-4 hours, with adequate intake/output.
What happens when the clinical status shows poor hemodynamic status in dengue with compensated shock?
Reassess hematocrit (HCT), and if HCT is increasing, administer isotonic crystalloids at 10-20 ml/kg/hour for 1 hour, then reassess.
What should be done if the hematocrit (HCT) shows improvement in dengue with compensated shock?
If HCT improves, continue fluids at a rate of 7-10 ml/kg/hour for 2 hours.
Q
What is the recommended action if the hematocrit (HCT) shows decreasing levels in dengue with compensated shock?
Blood transfusion should be considered if HCT decreases, indicating significant blood loss.
What is the cause of hypotensive (hypovolemic) shock?
The cause is loss of intravascular volume, often due to dehydration, blood loss, or fluid shifts.
What are the effects of hypotensive (hypovolemic) shock?
The effects include reduced cardiac output, hypotension, reduced organ perfusion, organ dysfunction, and potentially multiorgan failure.
What is the result of reduced cardiac output in hypotensive (hypovolemic) shock?
Reduced cardiac output leads to insufficient blood flow to organs and tissues, resulting in hypotension and impaired organ perfusion.
How does hypotensive (hypovolemic) shock affect organ function?
Inadequate blood flow leads to organ dysfunction, as vital organs do not receive enough oxygen and nutrients.
What severe consequence can occur in hypotensive (hypovolemic) shock if left untreated?
Multiorgan failure can occur due to prolonged reduced organ perfusion, leading to irreversible damage to organs.
What is the first step in treating dengue with hypotensive shock (Group C)?
The first step is to administer an isotonic crystalloid or colloid bolus of 20 ml/kg over 15 minutes.
What should be monitored in patients with dengue and hypotensive shock (Group C)?
Fluid intake/output, lab tests (including organ function tests and hematocrit (HCT)), and vital signs should be monitored, with vital signs checked hourly.
After the initial bolus of fluid in hypotensive shock, what is the next step if the patient’s condition improves?
If the patient’s condition improves, continue with isotonic crystalloids/colloid infusion at a rate of 10 ml/kg/hour for 1 hour.
What should be done if the patient’s haemodynamic status remains poor in hypotensive shock?
If the status remains poor, reassess hematocrit (HCT) and administer isotonic crystalloids at 10-20 ml/kg/hour for 1 hour.
How should fluid administration be adjusted in hypotensive shock based on clinical improvement?
If improvement occurs, reduce fluid administration:
5-7 ml/kg/hour for 1-2 hours.
3-5 ml/kg/hour for 2-4 hours.
2-3 ml/kg/hour for 2-4 hours.
Finally, fluids can be discontinued after reassessment.
What is the next step if the hematocrit (HCT) is decreasing during treatment of hypotensive shock in dengue?
If HCT is decreasing, a blood transfusion is indicated.
What should be monitored in patients with dengue and warning signs (Group B)?
Fluid intake/output, full blood count (FBC), and vital signs (checked every 4 hours) should be monitored.
How should fluid intake be managed for patients with dengue and warning signs?
Ensure adequate fluid intake and monitor for vital signs of shock and further warning signs. If fluid intake is inadequate, hematocrit (HCT) should be monitored and IV isotonic crystalloid solution should be administered.
What is the initial rate for IV fluid administration for dengue with warning signs?
The initial IV fluid rate is 5-7 mL/kg/hour for the first 1-2 hours.
How should fluid administration be adjusted after the first 1-2 hours in dengue with warning signs?
fter 1-2 hours, if needed, reduce the rate to 3-5 mL/kg/hour for 2-4 hours.
What should be done if the patient’s clinical status does not improve after initial treatment?
If the patient’s clinical status does not improve, increase IV fluid rate to 5-10 mL/kg/hour for 1-2 hours and continue to monitor clinical status and HCT.
When should IV fluids be continued for dengue with warning signs (Group B)?
If the patient’s condition improves, continue IV fluids at 3-5 mL/kg/hour for another 2-4 hours while continuing to monitor clinical status and HCT.
What should be monitored for patients with dengue and compensated shock (Group C)?
Fluid intake/output, organ function tests, hematocrit (HCT), and vital signs (monitored every 1-2 hours).
How should fluids be managed for patients with dengue and compensated shock?
Start with fluid monitoring and assess clinical status. If the patient’s condition improves, reduce the fluid rate to 5-7 mL/kg/hour for 2-4 hours.
What should be done if the patient shows further improvement in compensated shock (Group C)?
If further improvement occurs, reduce fluids to 3-5 mL/kg/hour for 2-4 hours and continue monitoring for adequate intake/output. If intake is adequate, fluids should be discontinued.
What should be done for poor hemodynamic status in dengue with compensated shock?
For poor hemodynamic status, reassess HCT and consider administering isotonic crystalloids at 10-20 mL/kg/hour for 1 hour. Reassess after 1 hour and adjust as necessary.
How should fluid administration be adjusted if HCT is increasing during compensated shock treatment?
If HCT is increasing, continue isotonic crystalloids at 7-10 mL/kg/hour for the next 2 hours.
What is the next step if HCT is decreasing during treatment of dengue with compensated shock?
If HCT is decreasing, consider administering a blood transfusion.
What type of RNA does the Flaviviridae family have?
The Flaviviridae family has +ssRNA (~11kb in size).
What are the structural proteins of the Flaviviridae family?
The structural proteins include Capsid (C), Membrane (M), and Envelope (E).
What are the non-structural proteins of the Flaviviridae family?
The non-structural proteins are NS1, NS2A-B, NS3, NS4A-B, and NS5.
What is the genome homology percentage within the Flaviviridae family?
The genome homology within the Flaviviridae family is about 65%.
What type of virus is Dengvaxia®?
Dengvaxia® is an attenuated virus vaccine for dengue.
What is the vaccination schedule for Dengvaxia®?
The Dengvaxia® vaccination schedule involves 3 doses, given 6 months apart.
How long does Dengvaxia® provide longevity of protection?
Dengvaxia® provides protection for around 6 years post the final vaccination.
What are the FDA conditions for use of Dengvaxia®?
The FDA conditions for use are:
Age 9-16
Reside in endemic area
Confirmed seropositive
What is the issue with Dengvaxia® in seronegative individuals?
There is a risk of severe dengue in seronegative individuals.
Is Dengvaxia® available for travelers?
Dengvaxia® is not available to travelers.
What type of virus is Qdenga®?
Qdenga® is an attenuated virus vaccine for dengue.
What is the vaccination schedule for Qdenga®?
The Qdenga® vaccination schedule involves 2 doses, given 3 months apart.
How long does Qdenga® provide longevity of protection?
Qdenga® provides protection for approximately 4.5 years post the final vaccination.
What are the MHRA conditions for use of Qdenga® in 2023?
The MHRA conditions for use are:
Age 4+
Confirmed seropositive
Planning to travel to a dengue hotspot
What is the issue with Qdenga® in seronegative individuals?
There is a risk of severe dengue in seronegative individuals.
Why was Qdenga® withdrawn by the FDA?
The FDA withdrew Qdenga® due to safety concerns.
What is the sequence homology of the E protein in the context of dengue vaccines?
The E protein in dengue vaccines has 50% sequence homology across the different serotypes.
What is Antibody Dependent Enhancement (ADE) in dengue?
Antibody Dependent Enhancement (ADE) occurs when previous infection or a poor vaccination response leads to enhanced infection. It is a main driver of severe dengue progression.
: How does ADE contribute to severe dengue progression?
ADE leads to more severe disease progression by facilitating the entry of the virus into immune cells, exacerbating the immune response.
What is D1ME100 in the context of dengue vaccines?
D1ME100 is a DNA vaccine specifically designed to target DENV-1 (Dengue virus serotype 1).
What type of vaccine is D1ME100 for dengue?
D1ME100 is a DNA vaccine, which contains genetic material to stimulate an immune response against DENV-1.
What is the target of D1ME100 in terms of dengue virus?
The target of D1ME100 is Dengue virus serotype 1 (DENV-1).
What type of vaccine is V180 (DEN-80E)?
V180 (DEN-80E) is a subunit vaccine designed for dengue.
xWhat component of the dengue virus does V180 target?
V180 targets a truncated form of the E protein of the dengue virus, which is 80% of the full-length E protein.
What is unique about the E protein in V180 (DEN-80E)?
The E protein in V180 is truncated, lacking the membrane anchor, making it purifiable for vaccine production.
Can V180 be used for all serotypes of the dengue virus?
Yes, V180 can be made for each dengue serotype and has the potential to be tetravalent.
What were the findings from the early Phase 1 clinical trials of V180?
In the early Phase 1 clinical trials, V180 (DEN-80E) was administered in 3 injections over 6 months, with 10 μg and 50 μg doses being well tolerated.
What type of vaccine is TDEV-PIV?
TDEV-PIV is an inactivated dengue vaccine.
How many serotypes of dengue does TDEV-PIV protect against?
TDEV-PIV is tetravalent, meaning it provides protection against all four dengue serotypes.
Which dengue virus proteins does TDEV-PIV target?
TDEV-PIV generates antibodies against the E (envelope), M (membrane), C (capsid), and NS1 proteins of the dengue virus.
What were the results of the Phase 1 trials of TDEV-PIV?
TDEV-PIV showed good immunogenicity and was well tolerated in Phase 1 trials.
What is the main treatment approach for dengue?
The treatment of dengue largely depends on fluid management.
Why are NSAIDs contraindicated in dengue treatment?
NSAIDs are contraindicated due to their bleeding risk, which is heightened in dengue.
Why must dengue vaccines protect against all 4 serotypes?
Dengue vaccines must protect against all 4 serotypes because protection against only a single serotype increases the risk of severe dengue.
How can Tfh cell activation influence dengue vaccine efficacy?
Tfh cell activation may increase vaccine efficacy, potentially enhancing immune response to the dengue virus.
What are the conditions for the approval of Dengvaxia®?
Dengvaxia® is currently approved for ages 9-16 in endemic areas.
What types of dengue vaccines are currently in Phase 1 trials?
DNA, inactivated virus, and subunit vaccines are currently in Phase 1 trials for dengue.
How is dengue fever managed? What are the pharmacological contraindications?
Dengue fever is primarily managed with fluid replacement (oral or intravenous) to prevent dehydration. Paracetamol is used for fever control, while NSAIDs are contraindicated due to their risk of bleeding. Steroids and antibiotics are not routinely used unless there is a secondary infection.
What is compensated shock and how is it treated in dengue?
Compensated shock in dengue occurs when there is reduced circulatory volume but the body compensates to maintain normal blood pressure. Signs include tachycardia, peripheral vasoconstriction, and reduced urine output.
Treatment:
Fluid monitoring and IV isotonic crystalloids (5-7 mL/kg/hour for 2-4 hours).
Adjust fluids based on clinical status and hematocrit (HCT).
What is hypovolemic shock and how is it treated in dengue?
Hypovolemic shock is caused by severe fluid loss, leading to reduced cardiac output, hypotension, and organ dysfunction.
Treatment:
IV isotonic crystalloids or colloids bolus (20 mL/kg in 15 minutes).
Monitor HCT, clinical status, and vital signs.
If HCT increases, continue isotonic fluids (10-20 mL/kg/hour); if HCT decreases, consider blood transfusion.
What are the key strategies in the development of dengue vaccines?
Key dengue vaccine strategies include:
Attenuated virus vaccines (e.g., Dengvaxia®) targeting all four serotypes.
DNA vaccines that induce immune responses to the virus.
Inactivated virus vaccines, which stimulate immunity without causing disease.
Subunit vaccines targeting specific viral proteins, such as the E protein.
Each vaccine has advantages and challenges, such as ensuring efficacy against all four serotypes and minimizing the risk of antibody-dependent enhancement (ADE), where a prior infection or vaccination with a single serotype may worsen future disease.
What are the challenges in developing a dengue vaccine?
Ensuring protection against all four serotypes of the virus.
Preventing antibody-dependent enhancement (ADE), where a vaccine or previous infection can make future infections more severe.
Balancing efficacy and safety, especially considering variations in the population’s prior exposure to the virus
Why should vaccines be used to prevent dengue?
Dengue causes significant morbidity and mortality, especially in tropical and subtropical regions.
Vaccination can drastically reduce infection rates and severity of the disease, alleviating the public health burden.
Vaccines can also reduce the economic impact of dengue outbreaks and lower healthcare costs by preventing severe cases and hospitalizations.
