Characterisation of Dengue Vaccine-induced Specific Immunity in Vaccinees With and Without Prior Exposure to Flavivirus Infections or Vaccination

Characterisation of Dengue Vaccine (Qdenga®, TAK-003)-Induced Humoral and Cellular Specific Immunity in Vaccinees With and Without Prior Exposure to Flavivirus Infections or Vaccination

The goal of this observational study is to learn about the immunity induced by the Qdenga® vaccine in vaccinees.

Participants that will receive the Dengue vaccine as part of their routine before a travel will be asked to undergo a blood sample at the time of administration of the first dose (T0), 24-48 hours after the first dose (T1) of the vaccine, immediately before the second dose (T2 ) and one to two months after the second dose (T3). Possibly a further sample will be collected within 2 years.

This is a non-profit, single-center, drug-based observational study whose primary objective is to characterize dengue-specific humoral and cellular immunity induced by the Qdenga® vaccine in vaccinees.

The study involves the enrollment of all pediatric subjects (age ≥ 4 years) and adults who present themselves at the DITM travel clinic for the administration of the Dengue vaccine; 402 patients are expected to be enrolled and will be asked to undergo a blood sample at the time of administration of the first dose (T0), 24-48 hours after the first dose (T1) of the vaccine, immediately before the second dose (T2 ) and one to two months after the second dose (T3). Possibly a further sample will be collected within 2 years (T4). The samples thus collected will be analyzed for the characterization of innate immunity, the characterization of cellular immunity and the characterization of the humoral response.

Inclusion Criteria:

• Subjects of both sexes presenting to the DITM to receive the anti-DENV vaccine whether or not they have had a history of prior DENV or other flaviviruses infection or a history of prior vaccination against other flaviviruses. These data will be recorded in the study CRF.
• Age >= 4 years.
• Signed informed consent.

Exclusion Criteria:

• Age < 4 years.
• Absence of signed informed consent.