NCT05592756

Brief Summary

This study will be an epidemiological inquiry, in communicating confirmed measles cases. The contacts of the index cases will be asked about the measles diagnosis and previous measles vaccination, and will have their vaccination cards checked. They will also be asked about blocking vaccination (opportune or not opportune) and about the development or not of symptoms. Thus, the investigators will have a group of people exposed to infection with a history of vaccination for measles prior to the outbreak versus a group of people exposed without previous vaccination. The frequency of measles cases will be compared in those two groups, allowing to analyze the effectiveness of the vaccine for individual protection. The effectiveness of the vaccine in preventing the spread of the disease will be analyzed, comparing the relative risk of the vaccine history of contact, in the subgroups of index cases with and without previous measles vaccination. The proposed study will involve the collection and analysis of contact data from measles cases oriented to compare vaccinated and unvaccinated, differing from health surveillance actions. This is based on an exhaustive search for contacts of measles cases, preferably aimed at detecting susceptible individuals, with the purpose of implementing blocking vaccination and interrupting the transmission chain. The proposed study seeks a representation of contacts, without the intention of being exhaustive in the search and detection, but prioritizing selection without bias for one of the exposure groups (vaccination). The results may provide technical and scientific support for future decisions by the Ministry of Health regarding the primary immunization schedule, the priority of the age group in vaccination campaigns, the identification of susceptible individuals, and the assessment of the need for a 3rd dose of the vaccine, for measles.

Trial Health

87
On Track

Trial Health Score

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

Enrollment
2,964

participants targeted

Target at P75+ for all trials

Timeline
Completed

Started Apr 2020

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

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

April 6, 2020

Completed
1.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 31, 2021

Completed
7 months until next milestone

Study Completion

Last participant's last visit for all outcomes

March 31, 2022

Completed
7 months until next milestone

First Submitted

Initial submission to the registry

October 20, 2022

Completed
5 days until next milestone

First Posted

Study publicly available on registry

October 25, 2022

Completed
Last Updated

June 13, 2023

Status Verified

June 1, 2023

Enrollment Period

1.4 years

First QC Date

October 20, 2022

Last Update Submit

June 12, 2023

Conditions

Keywords

soroprotegido

Outcome Measures

Primary Outcomes (1)

  • Measles case after index case

    Measles case after index case, confirmed by laboratory or epidemiological link

    18 days after the index case

Eligibility Criteria

Sexall
Healthy VolunteersYes
Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Communicants referring to index cases will be interviewed. Approximately 846 contacts, with 5% of losses this amount will be 890 contacts (445 vaccinated and 445 not vaccinated). Assuming an average of 20 contacts per index case, we will need approximately 45 index cases.

You may qualify if:

  • Characterize contact with confirmed case of measles at home, waiting room, work, etc.
  • Both sexes.
  • Willingness to answer the study questionnaire.
  • Have had contact with the index case, 6 days before the appearance of the rash, up to 18 days after.
  • Have proof of vaccination (or authorize access to health unit vaccination records) or if you no longer have a vaccination card, state whether you have had a vaccine in the past or not.
  • Willingness to provide name, address, telephone and other information so that the principal investigator and his team can contact you, if necessary (example: in case of missed visit).
  • Willingness to strictly follow the study protocol.
  • At least one of the legal guardians for the research participants must be able to understand and sign the Free and Informed Consent Form. If those responsible are unable to sign (illiterate), the IC can be signed by an impartial witness who has accompanied the entire procedure
  • For those over 6 years old, and under 18 years old, ability to understand and sign the Informed Consent Form.
  • For those over 18, ability to understand and sign the Informed Consent Form.

You may not qualify if:

  • Contact with the index case outside the contagion period, that is, after 18 days.
  • Inform that you do not know the vaccination status.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Eliane Matos dos Santos

Rio de Janeiro, ematos@bio.fiocruz.br, Brazil

Location

MeSH Terms

Conditions

Measles

Condition Hierarchy (Ancestors)

Morbillivirus InfectionsParamyxoviridae InfectionsMononegavirales InfectionsRNA Virus InfectionsVirus DiseasesInfections

Study Design

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

Study Record Dates

First Submitted

October 20, 2022

First Posted

October 25, 2022

Study Start

April 6, 2020

Primary Completion

August 31, 2021

Study Completion

March 31, 2022

Last Updated

June 13, 2023

Record last verified: 2023-06

Locations