Dengue Vaccine (Dengvaxia, CYD-TDV):
- Dosing:
- 3 doses, 6 months apart (0, 6, 12 months).
- Rationale: The 3-dose schedule is based on clinical trials showing sustained efficacy.
- Duration of Protection:
- Up to 6 years post-vaccination (based on long-term follow-up data).
- Rationale: Efficacy wanes over time, with the highest protection in the first few years.
- Prevention Rate (Efficacy):
- ~60% against symptomatic dengue (varies by serotype).
- ~80% against severe dengue and hospitalization.
- Rationale: Efficacy is higher in individuals with prior dengue infection (seropositive) compared to seronegative individuals.
- Key Considerations:
- WHO Recommendation: Vaccination only for seropositive individuals (prior dengue infection) due to increased risk of severe disease in seronegative recipients.
- Safety: Avoid in seronegative individuals to prevent vaccine-enhanced disease.