NCT03338231

Brief Summary

Yellow fever is an acute viral disease transmitted by mosquitoes in South America, Central America and Africa. It is more prevalente in males gender and the age above 15 years due to the greater exposure in the wild endemic area of yellow fever. According to the World Health Organization (WHO), a single dose of the yellow fever vaccine is sufficient to maintain protective immunity against yellow fever for a lifetime, therefore a booster dose is not required. This issue is difficult to evaluate because there is no serological correlate of protection against yellow fever and seropositivity is defined with several cut-off points. Although studies indicate that the duration of protection after vaccination is long, many studies have demonstrated a reduction of the antibody titrer over the years. Consequently, there is more concern about people who live in endemic areas. For this reason, Brazil recommends revaccinating once at least until additional studies are performed. It is important to know the duration of immunity induced by lower doses of YF vaccine. In our knowledge, there is a lack of clinical studies evaluating the immunity duration of the yellow fever vaccine with lower doses. This information is relevant to subsidize the routine recommendation of YF vaccine fractional dose for adults.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
374

participants targeted

Target at P75+ for all trials

Timeline
Completed

Started Mar 2017

Shorter than P25 for all trials

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

March 27, 2017

Completed
5 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

September 4, 2017

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

September 4, 2017

Completed
2 months until next milestone

First Submitted

Initial submission to the registry

November 1, 2017

Completed
8 days until next milestone

First Posted

Study publicly available on registry

November 9, 2017

Completed
Last Updated

November 9, 2017

Status Verified

November 1, 2017

Enrollment Period

5 months

First QC Date

November 1, 2017

Last Update Submit

November 7, 2017

Conditions

Keywords

Immunity duration

Outcome Measures

Primary Outcomes (1)

  • Number of seropositivity participants to YF vaccine as assessed by PRNT.

    To evaluate the seropositivity by the means of the neutralizing antibody dosage in the participants of the "Dose-response study of the 17DD yellow fever vaccine produced by Bio-Manguinhos/Fiocruz" realized in 2009

    8 years after the 1 st dose of yellow fever vaccine

Secondary Outcomes (1)

  • Individual repertoire of immunoglobulins profile as assessed by the PEPperPRINT and phenotypic/functional anti-amaryl memory cell analyse.

    8 years after the 1 st dose of yellow fever vaccine

Eligibility Criteria

Age18 Years+
Sexmale
Age GroupsAdult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Male adults who received the first dose of the yellow fever vaccine in 2009 when they participated in the "Dose-response study of the yellow fever vaccine 17DD produced by Bio-Manguinhos / Fiocruz

You may qualify if:

  • Participated in the "Dose-response study of the yellow fever vaccine 17DD produced by Bio-Manguinhos / Fiocruz" in 2009.
  • Not been revaccinated during the "Dose-response study of the yellow fever vaccine 17DD produced by Bio-Manguinhos / Fiocruz" of 2009.
  • Not having received another dose of the 17DD yellow fever vaccine after participating in the 2009 "Bio-Manguinhos / Fiocruz" 17DD yellow fever vaccine dose-response study.
  • Provide name, address, telephone and other information so that you can contact if necessary.
  • Ability to understand and sign the TCLE.

You may not qualify if:

  • Impossibility or refusal to collect blood

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Bio-Manguinhos/Fiocruz

Rio de Janeiro, 21040-360, Brazil

Location

Related Publications (1)

  • de Menezes Martins R, Maia MLS, de Lima SMB, de Noronha TG, Xavier JR, Camacho LAB, de Albuquerque EM, Farias RHG, da Matta de Castro T, Homma A; Collaborative Group for Studies on Duration of Immunity from Yellow Fever Vaccine. Duration of post-vaccination immunity to yellow fever in volunteers eight years after a dose-response study. Vaccine. 2018 Jun 27;36(28):4112-4117. doi: 10.1016/j.vaccine.2018.05.041. Epub 2018 May 18.

Study Officials

  • Reinaldo M Martins, PhD

    Oswaldo Cruz Foundation

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
observational
Observational Model
OTHER
Time Perspective
RETROSPECTIVE
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

November 1, 2017

First Posted

November 9, 2017

Study Start

March 27, 2017

Primary Completion

September 4, 2017

Study Completion

September 4, 2017

Last Updated

November 9, 2017

Record last verified: 2017-11

Data Sharing

IPD Sharing
Will not share

Locations