Markers of T Cell Suppression: Antimalarial Treatment and Vaccine Responses in Healthy Malian Adults

Background:

People with malaria often show altered immune responses to many illnesses and vaccines. This means that the malaria might cause immune suppression. It is not clear how or which vaccines are impacted by malaria. It is also not clear if the impacts are such that people should be preemptively treated before they get vaccinations. Researchers want to see if there is a link between taking an antimalaria drug prior to getting vaccines and the immune response to those vaccines. To do this, they will study people who are taking part in certain NIAID studies.

Objectives:

To compare the proportion of PD1+ CD4 T cells among all T cells in vaccine immune responses in adults who have or have not received antimalarials prior to getting a Menactra vaccine.

Eligibility:

Healthy Malian adults who:

Were previously enrolled in NIAID Protocol 13-I-N109 or 15-I-0044

Reside in Bancoumana and neighboring villages

Are not pregnant

Design:

Participants will be screened with a physical exam.

Participants will get the vaccines listed below as part of Protocol 13-I-N109 or 15-I-0044. This study will follow their schedule.

At each visit, participants will give a blood sample. They will also have a physical exam. Each visit will last 1 to 2 hours.

At visit 1, participants will get a hepatitis vaccine.

Two weeks later, participants may get the antimalarial drug Coartem . They will be chosen at random.

Two weeks later, participants will get Menactra .

Participants will have 5 follow-up visits after they get Menactra .

The study will last up to 4 months.

...

Study Overview

Status

Completed

Conditions

Detailed Description

Malaria patients often show altered immune responses, not only to malaria parasites but also to unrelated pathogens (eg, HIV, EBV, salmonella, helminthes) and antigens, including routine vaccines, suggesting that there is an active immune suppression or more accurately perhaps, immunomodulation, occurring during the course of malaria infection. How and which vaccines are impacted by clinical malaria or asymptomatic parasitemia is not completely clear and nor is whether the impacts are significant enough to recommend delaying or pre-emptively treating individuals prior to vaccinations.

Up to 75 adults will be recruited from volunteers enrolled in NIAID protocol 13-I-N109 and NIAID protocol 15-I-0044 who after unblinding have opted to receive or complete the comparator vaccine series: Euvax (Hepatitis B) or TWINRIX (Hepatitis B) and Menactra (Meningococcal). This longitudinal study will be conducted in Bancoumana and neighboring villages in Mali. In September 2015, up to 50 adults presenting for their Vaccination #3 of Euvax will be enrolled from NIAID protocol 13-I-N109. In October 2015, up to 25 adults presenting for their Study Day 168 will be enrolled following unblinding from NIAID protocol 15-I-0044.

Following receipt of their Euvax B or TWINRIX vaccination, subjects will be randomized to receive or not receive a course of Coartem (artemether-lumefantrine) 2 weeks prior to their scheduled Menactra vaccination. They will then be followed for approximately 3 months post receipt of Menactra . Samples will be collected from the adults at the time of prior to and following receipt of both vaccinations and assessed in ex vivo assays for markers of T-cell suppression as the primary outcome of this study. For our secondary outcomes, we will examine levels of regulatory T cells, measure T cell responses in stimulation assays, and survey parasitemia by blood smear and by polymerase chain reaction assays. We expect that levels of T-cell suppression and regulatory T cells will be similar between groups before antimalarial treatment or malaria infection, but after treatment or in those subjects that remain uninfected these levels will be significantly lower as compared to the untreated and or infected subjects.

Study Type

Observational

Enrollment (Actual)

49

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Bamako, Mali
        • Malaria Research and Training Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 50 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

  • INCLUSION
  • Enrolled, completed unblinding, and have opted to receive the comparator vaccines in either NIAID Protocol 13-I-N109 or 15-I-0044
  • In good general health and without any clinically significant medical history
  • Willing to have blood samples stored for future research
  • Known resident of Bancoumana or surrounding area

EXCLUSION

  • Known to be pregnant (by history)
  • Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, endocrine, rheumatologic, autoimmune, hematological, oncologic, psychiatric, or renal disease by history and/or physical examination
  • Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the participant to understand and comply with the study protocol
  • Prior to Study Day 0, receipt of a live vaccine within the past 4 weeks or a killed vaccine within the past 2 weeks
  • Use of chronic (greater than or equal to 14 days) oral or intravenous corticosteroids (excluding topical or nasal) at immunosuppressive doses (eg, prednisone > 10 mg/day) or immunosuppressive drugs within 30 days of Study Day 0
  • Known allergies or contraindications to study treatment (Coartem [artemether//lumefantrine]) or vaccines (Euvax B or TWINRIX and Menactra )
  • Other condition that in the opinion of the investigator would jeopardize the safety or rights of a participant participating in the trial, interfere with the evaluation of the study objectives, or would render the subject unable to comply with the protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Proportion of T cells expressing PD-1 among all T cells on Study Day 42
Time Frame: Study Day 42
Study Day 42

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 4, 2015

Primary Completion (Actual)

September 4, 2015

Study Completion (Actual)

August 11, 2017

Study Registration Dates

First Submitted

September 5, 2015

First Submitted That Met QC Criteria

September 5, 2015

First Posted (Estimate)

September 9, 2015

Study Record Updates

Last Update Posted (Actual)

December 17, 2019

Last Update Submitted That Met QC Criteria

December 14, 2019

Last Verified

August 11, 2017

More Information

Terms related to this study

Other Study ID Numbers

  • 999915197
  • 15-I-N197

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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