Current Recommendations for Dengue Vaccines:
- Dengvaxia (CYD-TDV): Approved for individuals aged 9–45 years who have had at least one prior dengue infection (seropositive). Rationale: Risk of severe disease in seronegative individuals post-vaccination.
- Tetravalent Dengue Vaccine (TDV, Takeda): Recently approved (2023) for individuals aged 4–16 years, regardless of prior infection status. Rationale: Designed to mitigate the risk of severe disease in seronegative recipients.
- Key Considerations for Seronegative Individuals:
- Dengvaxia: Not recommended due to increased risk of hospitalization and severe disease upon natural infection post-vaccination (WHO, 2018).
- TDV (Takeda): Potential for broader use, but long-term safety data in seronegative populations are still under review. Rationale: Mechanism of action (live-attenuated) may confer protection without the same risks as Dengvaxia.
- Evidence-Based Context:
- Dengvaxia Trials: CAPTURE study (2023) showed 80% efficacy in seropositive individuals; no data for seronegative.
- TDV Trials: Phase 3 trials (2023) suggest efficacy in both seropositive and seronegative, but post-marketing surveillance is ongoing.
Conclusion: Current guidelines prioritize seropositive individuals for Dengvaxia. TDV may expand access, but further data are needed for seronegative populations.