If my patient has no laboratory evidence of previous infection at age 9 years and vaccination is deferred, should I re-test the patient when they are older to see if they have acquired a DENV infection while they are still age-eligible for vaccination?

Patients with a negative test should be re-tested every 1 or 2 years (while remaining between the ages of 9 through 16 years) or based on the clinical judgment of the health care provider.

CDC recommends that children and adolescents who are acutely ill with dengue virus infection should wait at least 6 months after the date dengue virus infection is confirmed to begin the vaccine series. https://www.cdc.gov/dengue/hcp/vaccine/schedule-dosing.html.