Immunogenicity of Fractional One-fifth and One-half Doses of Yellow Fever Vaccine Compared to Full Dose in Children 9-23 Months Old
Yellow Fever
About this trial
This is an interventional prevention trial for Yellow Fever
Eligibility Criteria
Inclusion Criteria:
- Age 9 to 23 months at the time of enrollment
- Intent to stay in the health center catchment area and availability to do study visits at 2 weeks, 4 weeks, and 12 months after enrollment date
- Informed consent signed by parent/guardian for child's participation in the study, including blood sample collections at 4 week and 12 month visits post-vaccination
- Willingness of parent/guardian to be contacted by study personnel by telephone and through home visits if they cannot be reached by telephone.
Exclusion Criteria:
- Verbal or written report of previous vaccination against YF
- Verbal or documented history of YF disease
Contraindication for YF vaccine including:
- Allergy to eggs, gelatin, or neomycin
- Severe immune deficiency immunological including symptomatic HIV infection and HIV- infected persons with CD4 T-cell counts ≤200 cells/ mm³, primary immunodeficiencies, having received immunosuppressive doses of oral or injectable corticosteroids (or equivalent), having received immunomodulatory or chemotherapeutic agents
- Thymus disorder
- History of malignant neoplasm or recent hematopoietic stem cell transplantation
- Serious illness/fever (mild illness without fever is not an exclusion criterion)
Administration of immunoglobulins or other blood derivative within 6 months of enrollment in the study or during the study
a. Exception: children with a history of Kawasaki disease who received gammaglobulin cannot be enrolled if they received it in the previous 11 months.
- Administration of any other attenuated viral vaccine in the month prior to enrollment, or if the administration of any other attenuated viral vaccine is expected during the month after enrollment. Note: the administration of measles vaccine on the same day as YF vaccination is not a contraindication; however, if Uganda introduces measles-rubella vaccine (MR), participants will not be able to receive MR on the same day as YF vaccine due to possible interference between rubella and YF vaccine. In this situation, children will have to delay study enrollment until 1 month after MR vaccination.
- Participating in another clinical drug trial of a drug, vaccine, or medical device
- Severely underweight defined as ≤ 3rd percentile in the height/weight tables
- Severe reaction to prior vaccination
Any chronic or other condition that, in the opinion of the study staff, represents a health risk to the participant or interferes with the evaluation of the response to the vaccine
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Sites / Locations
Arms of the Study
Arm 1
Arm 2
Arm 3
Experimental
Experimental
Experimental
One-fifth fractional dose
One-half fractional dose
Full dose
One-fifth fractional dose (0.1 ml) of Yellow Fever 17DD Vaccine administered subcutaneously
One-half fractional dose (0.25 ml) of Yellow Fever 17DD Vaccine administered subcutaneously
Full dose (0.5 ml) of Yellow Fever 17DD Vaccine administered subcutaneously