CompletedPhase 4

Immunogenicity of Fractional One-fifth and One-half Doses of Yellow Fever Vaccine Compared to Full Dose in Children 9-23 Months Old

United States1,788 participantsStarted 2018-11-01

Plain-language summary

A randomized clinical trial comparing fractional dose Yellow Fever vaccination to the full dose among children aged 9-23 months in Uganda. Children will have immune response assessed at baseline, 4 weeks, and 12 months after vaccination. Enrolled participants will be randomized to one of three arms: A. One-fifth fractional dose (0.1 ml) administered subcutaneously B. One-half fractional dose (0.25 ml) administered subcutaneously C. Full dose (0.5 ml) administered subcutaneously

Who can participate

Age range

9 Months – 23 Months

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

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

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Immune response at 4 weeks in terms of seroconversion following vaccination

Timeframe: 4 weeks post vaccination

Trial details

NCT IDNCT03725618

SponsorCenters for Disease Control and Prevention

Sponsor typeFED

Study typeINTERVENTIONAL

Primary completion2021-09-01

View on ClinicalTrials.gov More Yellow Fever trials