Investigation of Serious Adverse Events Following Vaccination Against Yellow Fever: Emphasis on Genetic Basis and Biological Markers

Study Overview
=================
Brief Summary
-----------------
It concerns an investigation aiming to investigate genetic biological(s) marker(s) which allow to identify individuals who have risk of serious adverse events to the yellow fever vaccine. This testing is free of hypothesis, because these markers are still unknown. There is no intervention, and it is not possible to establish primary and secondary outcomes.

Detailed Description
-----------------
The rational for the immunological study by LATIM is the observation made by the group that individuals vaccinated with the 17DD yellow fever vaccine show significant alterations on the levels of expression of genes such as CLEC5A, IFNG, IL6, RNASEL, IRF7, IRF9, STAT2 e OAS1 (8). The study which will be conducted by the Rockefeller University will be focused in the qualitative analysis of the genome and exome of volunteers. The study in LATIM will be focused in the quantitative analysis of mRNA, which, together with the results of sequencing, may help in the search for biomarkers. As the expression of mRNA is restricted to the acute phase of the adverse event, it will be done only during the first 30 days after the beginning of the adverse event.

Official Title
-----------------
Investigation of Serious Adverse Events Following Vaccination Against Yellow Fever: Emphasis on Genetic Basis and Biological Markers

Conditions
-----------------
Drug-Related Side Effects and Adverse Reactions

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion criteria: Evidence of a systemic reaction in two or more organs within one month of vaccination with yellow fever vaccine; Laboratory evidence of yellow fever vaccine virus (at least one): Positive culture for more than 7 days after vaccination; RT-PCR ≥ 3 log10 PFU/mL at any day after vaccination; Positive RT-PCR more than 14 days after vaccination; Presence of vaccine virus in tissue by culture, RT-PCR or immunohistochemistry. Laboratory exclusion of relevant differential diagnosis such as leptospirosis, viral hepatitis and arboviruses. Cases not obeying these strict criteria but that could be plausibly YEL-AVD or YEL-AND may be included, if approved by the investigator or co-investigators. Exclusion Criteria: Cases with adverse event after yellow fever vaccine not severe.

Ages Eligible for Study
-----------------
Minimum Age: 9 Months
Maximum Age: 59 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------
What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Genetic markers | Whole exome sequencing (WES) will be performed in YEL-AVD cases. | Time frame: 5 years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
yellow fever vaccine, genetic factors, viscerotropic disease, neurological disease