Dengue doesn't mutate. But, what it does do is revert back to the wild form after attenuation for vaccines. If Sanofi's vaccine uses any attenuated live virus, the reversion to wild of one or more types in the vaccine would only show in expended trials.
The problem, tetravalent vaccines with live virus are fine for patients who have never had Dengue, but can be deadly for those who have had one of the four Dengue types. If the case, when a dose is administered that has a reverted form different from the Dengue type the subjcet previously had, then the patient gets not only Dengue fever, but can become DHF and/or DSS. Over the past 20 years 4 vaccine trials have resulted in declaring the vaccine unsafe following either Phase 2 or Phase 3 trials.
News 
Market Data 
Discover 
AI
