In-depth Notes on Science Policy and Medical Science Related to Dengue and COVID-19

Introduction to Science Policy in Medical Science

• Focus on the context of the COVID-19 pandemic in the Philippines.
• Discussion centers on vaccination programs and the history with dengue fever and the Dengvaxia vaccine.

Dengue Epidemic Overview

• Dengue is an endemic disease in the Philippines, often associated with high mortality, particularly among children.
• Characteristic vector: Aedes aegypti mosquito, identifiable by white and black bands, bites primarily during the daytime.

Related Diseases

• Aedes aegypti carries three significant viruses:
  1. Dengue
  2. Chikungunya
  3. Zika

Symptoms of Dengue and Comparison with Other Diseases

• Dengue Symptoms:
  • High fever (average 38.5°C to 39°C) and chills.
  • Mild arthritic joint pain.
  • Skin rashes (red spots) are prevalent.
  • Possible bleeding as a late manifestation leading to severe cases.
• Chikungunya Symptoms:
  • High fever similar to dengue.
  • Intense joint pain is more significant than in dengue.
  • Rashes may appear after 48 hours.
  • No bleeding.
• Zika Symptoms:
  • Moderate joint pain, red spots.
  • No fever or significant bleeding, but major health concerns for fetal development (microcephaly).

Dengue Virus Pathophysiology

• The dengue virus attacks blood vessel structures, causing bleeding due to weakened vascular integrity.
• Low platelet counts contribute to excessive bleeding complications.
• Three Stages of Dengue:
  1. Dengue Fever (DF): flu-like symptoms for 2-7 days.
  2. Dengue Hemorrhagic Fever: includes bleeding and requires immediate medical attention.
  3. Severe Dengue Shock Syndrome: critical condition involving organ failures due to severe bleeding.

Vaccination: Dengvaxia

• Vaccine Overview:
  • Dengvaxia is designed to protect against all four types of dengue.
  • Initial discussions of Dengvaxia highlighted concerns regarding safety of administration in previously unexposed individuals.
• Vaccine Rollout in the Philippines:
  • Sanofi’s Dengvaxia underwent multiple trial phases before approval.
  • First vaccine licensed in Asia, targeting those aged 9-60 years old, particularly effective post-dengue infection.
• Public Health Policy Concerns:
  • Post-marketing dangers were highlighted, especially for seronegative individuals (those without prior dengue exposure).

Vaccine Efficacy and Safety

• Concerns arose regarding insufficient testing or monitoring before widespread use.
• Subsequent trials indicated that seronegative individuals might experience higher risks when vaccinated.

Importance of Science Communication

• Effective communication regarding vaccination protocols is essential for public acceptance.
• The need for thorough public education on vaccination benefits and risks is critical, especially in light of previous vaccine controversies.

Role of Health Policy in Epidemics

• Decision-making in health policy (e.g., vaccine rollout) should consider scientific advice, statistical safety data, and public fears/premises.
• Example: The necessity of stakeholders including parents and health workers in the discussion surrounding vaccines like Dengvaxia and now COVID-19.

Conclusion

• Effective science communication can help bridge gaps between healthcare providers and the public during vaccination programs.
• Understanding mechanisms of vaccines and informed discussions can enhance public trust and acceptance in health policies, particularly in evolving situations like COVID-19 vaccination campaigns.