Important findings from a supplementary exploratory study on Dengvaxia® to assess long term safety and efficacy of Dengvaxia® from Phase IIb/III studies

Sanofi Pasteur would like to inform healthcare professionals about a review of the results from a supplemental exploratory study conducted by Sanofi Pasteur to further assess the long-term safety and efficacy of Dengvaxia^® from the Phase IIb/III efficacy studies. The results showed that in individuals who have not been previously infected by dengue virus, an increased risk of hospitalisation for dengue and clinically severe dengue has been observed in the long-term follow up of clinical trials. This increased risk was not observed in individuals who have been previously infected by the dengue virus. Healthcare professionals are advised to assess the dengue serostatus of an individual before vaccination. The package insert of Dengvaxia^® will be strengthened to include a new warning of this increased risk and long-term follow-up data from the study. Please refer to the letter for details.