UnknownNot Applicable

Complementary Study of the Duration of Post-vaccination Against Yellow Fever Immunity in Children

Brazil60 participantsStarted 2015-04

Plain-language summary

In a previous study by the researchers' group, the researchers' investigate the duration of yellow fever post-vaccination immunity in vaccinated children between 9 and 23 months of age. However, in this study, samples of children in the pre-vaccine period, also known as unvaccinated children samples (NV) have not been investigated. It is believed that to seek evidence about the immune status in the medium and long term after vaccination against yellow fever is necessary to investigate paired samples of children not vaccinated (NV), with re-evaluation 30-45 days after primary vaccination. The proposed study is to consolidate aspects of humoral (neutralizing antibodies) and cellular (phenotypic and functional parameters of T cells and memory B) by means of complementary longitudinal investigation children, 9-23 months old, unvaccinated (NV) and 30-45 days after primary vaccination.

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: Will be eligible for the study: * children 9-23 months of age; * both sexes; * children who will be vaccinated against yellow fever, whose parents or guardians sign the consent form. Exclusion Criteria: * children who received another vaccine within 30 days before or after the yellow fever vaccine; * children which have permanent or temporary immunosuppression, including those treated with corticosteroids at doses higher than 2 mg / kg, and those with disease autoimmune diseases, transient or permanent immunosuppression induced diseases (cancer, AIDS, etc.) or treatment (immunosuppressive drugs, radiotherapy, etc.). Corticosteroids (such as prednisone, dexamethasone) for less than two weeks, or by inhalation or topical use, do not indicate exclusion from the study, but must be registered in the questionnaire (Annex II); * children with hemoglobinopathies; * children with a history of blood transfusion or treatment with hyperimmune serum up to 90 days prior to blood collection.

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

Quantification of Humoral and cellular immunity after first yellow fever vaccination

Timeframe: Time 0 (immediately before) and Time 1 (30-45 days after) primary vaccination against yellow fever

Trial details

NCT IDNCT02990182

SponsorOswaldo Cruz Foundation

Sponsor typeOTHER

Study typeOBSERVATIONAL

Primary completion2017-04

View on ClinicalTrials.gov More Yellow Fever trials