Dengvaxia Efficacy Dependency on Serostatus: A Closer Look at More Recent Data

To the Editor—We read with concern the recent article by Yang and colleagues, "Dependency of Vaccine Efficacy on Pre-Exposure and Age: A Closer Look at a Tetravalent Dengue Vaccine" [1]. We agree that Dengvaxia was efficacious among children who were dengue seropositive at baseline, but it is important to mention that it is not known how long vaccinated seropositive individuals will be protected. More studies are necessary as this vaccine could be giving only a temporary boost to their immunity.