<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT02206451</url>
  </required_header>
  <id_info>
    <org_study_id>999914159</org_study_id>
    <secondary_id>14-I-N159</secondary_id>
    <nct_id>NCT02206451</nct_id>
  </id_info>
  <brief_title>Assessing Human-to-Mosquito Transmission in Volunteers Participating in Malaria Vaccine Candidate Trials in Mali</brief_title>
  <official_title>Assessing Human-to-Mosquito Transmission in Volunteers Participating in Malaria Vaccine Candidate Trials in Don(SqrRoot)(Copyright)gu(SqrRoot)(Copyright)Bougou Mali</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>National Institute of Allergy and Infectious Diseases (NIAID)</agency>
      <agency_class>NIH</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>National Institutes of Health Clinical Center (CC)</source>
  <brief_summary>
    <textblock>
      Background:&#xD;
&#xD;
      - Malaria is a disease that affects many people in Mali and in Africa. It is caused by germs&#xD;
      that are spread by mosquito bites. Researchers are creating vaccines that they hope will&#xD;
      prevent malaria infection and/or the spread of it.&#xD;
&#xD;
      Objective:&#xD;
&#xD;
      - To test if the PfSPZ vaccine can stop malaria spread by mosquitoes.&#xD;
&#xD;
      Eligibility:&#xD;
&#xD;
      - People currently enrolled in the ongoing PfSPZ malaria vaccine trial. Participants must be&#xD;
      willing to have uninfected mosquitoes bite them.&#xD;
&#xD;
      Design:&#xD;
&#xD;
        -  Participants will be able to take part in this study at every visit after receiving all&#xD;
           scheduled vaccinations.&#xD;
&#xD;
        -  Participants will be asked whether they are willing to participate in the procedures.&#xD;
           Female participants will have a pregnancy test.&#xD;
&#xD;
        -  Researchers will put about 60 mosquitoes in 2 or 3 cups (20 or 30 in each cup). They&#xD;
           will hold each cup to the participant s leg or arm so the mosquitoes can bite. These&#xD;
           mosquitoes do not carry germs and will take about 3 drops of blood total.&#xD;
&#xD;
        -  Participants will get a cream for any swelling or itching.&#xD;
&#xD;
        -  Participants will be checked the next day for any discomfort.&#xD;
&#xD;
        -  Participants may take part in this feeding test multiple times, if they are willing.&#xD;
&#xD;
        -  If participants have malaria parasites in their blood, they may be asked to take part in&#xD;
           another study. For this, they will sleep alone in their hut the night after the feeding&#xD;
           test. A study team will set up nets to collect mosquitoes that may have bitten the&#xD;
           participant overnight.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      A vaccine which interrupts malaria transmission (VIMT) is a critical tool to achieve the&#xD;
      ultimate goal of eradication of this disease. VIMTs work by inducing humoral responses in&#xD;
      vaccinated individuals that inhibit the development of malaria parasites in the mosquito, and&#xD;
      combined humoral and cellular responses that inhibit the establishment of infection in&#xD;
      humans. Overall efficacy of these vaccines is evaluated by measuring reduction of infection&#xD;
      and clinical cases among vaccinees and the parasite infectivity to mosquitoes,&#xD;
      (human-to-mosquito transmissibility), before and after vaccination, and with or without&#xD;
      vaccination. One of the candidate VIMTs, the PfSPZ Vaccine, is currently being tested in Mali&#xD;
      for safety, tolerance, and immunogenicity.&#xD;
&#xD;
      The objective of this Feeding Assay Protocol is to explore the effect of the PfSPZ Vaccine,&#xD;
      on interrupting human-to-mosquito transmission. Individuals from the the PfSPZ Vaccine trial&#xD;
      in 2014 who also consent to be enrolled in this Feeding Assay Protocol will be eligible to&#xD;
      participate in procedures including direct skin feeds (DSF) and experimental huts (EH). The&#xD;
      human-to-mosquito transmission will be evaluated by examining the presence of malaria&#xD;
      parasites in the midgut of mosquitoes fed on study participants. The human-to-mosquito&#xD;
      transmission by DSF and EH assay methods will be analyzed for potential correlation.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date>July 16, 2014</start_date>
  <completion_date type="Actual">July 16, 2014</completion_date>
  <primary_completion_date type="Actual">July 16, 2014</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Case-Only</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>Measurement of infection/infectivity incidences</measure>
    <time_frame>1 year</time_frame>
  </primary_outcome>
  <secondary_outcome>
    <measure>Measurement of infection intensity for a given mosquito that was fed on a given subject</measure>
    <time_frame>1 year</time_frame>
  </secondary_outcome>
  <enrollment type="Actual">87</enrollment>
  <condition>Malaria</condition>
  <eligibility>
    <criteria>
      <textblock>
        -  INCLUSION CRITERIA:&#xD;
&#xD;
          -  Currently enrolled in the PfSPZ Vaccine trial.&#xD;
&#xD;
          -  Willingness to participate in the study as evidenced by signing the informed consent&#xD;
             document, or by fingerprinting the consent document and obtaining the signature of a&#xD;
             witness.&#xD;
&#xD;
        EXCLUSION CRITERIA:&#xD;
&#xD;
          -  Refusal to participate&#xD;
&#xD;
          -  Known history of abnormal reaction to mosquito bites&#xD;
&#xD;
          -  Any condition that in the opinion of the investigator would jeopardize the safety or&#xD;
             rights of a volunteer participating in the DSF or EH procedures or would render the&#xD;
             volunteer unable to comply with the Feeding Assay Protocol.&#xD;
&#xD;
          -  Pregnancy&#xD;
&#xD;
          -  Any condition that in the opinion of the investigator would withdraw the volunteer&#xD;
             from vaccine trial.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>35 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Sara A Healy, M.D.</last_name>
    <role>Principal Investigator</role>
    <affiliation>National Institute of Allergy and Infectious Diseases (NIAID)</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Malaria Research and Training Center</name>
      <address>
        <city>Bamako</city>
        <country>Mali</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Mali</country>
  </location_countries>
  <reference>
    <citation>Diallo M, Toure AM, Traore SF, Niare O, Kassambara L, Konare A, Coulibaly M, Bagayogo M, Beier JC, Sakai RK, Toure YT, Doumbo OK. Evaluation and optimization of membrane feeding compared to direct feeding as an assay for infectivity. Malar J. 2008 Dec 2;7:248. doi: 10.1186/1475-2875-7-248.</citation>
    <PMID>19055715</PMID>
  </reference>
  <reference>
    <citation>Gouagna LC, Yao F, Yameogo B, Dabire RK, Ouedraogo JB. Comparison of field-based xenodiagnosis and direct membrane feeding assays for evaluating host infectiousness to malaria vector Anopheles gambiae. Acta Trop. 2014 Feb;130:131-9. doi: 10.1016/j.actatropica.2013.10.022. Epub 2013 Nov 18.</citation>
    <PMID>24262642</PMID>
  </reference>
  <reference>
    <citation>Moorthy VS, Newman RD, Duclos P, Okwo-Bele JM, Smith PG. Assessment of the RTS,S/AS01 malaria vaccine. Lancet Infect Dis. 2013 Apr;13(4):280-2. doi: 10.1016/S1473-3099(13)70047-1. Epub 2013 Mar 1. No abstract available.</citation>
    <PMID>23454165</PMID>
  </reference>
  <verification_date>June 29, 2016</verification_date>
  <study_first_submitted>July 31, 2014</study_first_submitted>
  <study_first_submitted_qc>July 31, 2014</study_first_submitted_qc>
  <study_first_posted type="Estimate">August 1, 2014</study_first_posted>
  <last_update_submitted>December 14, 2019</last_update_submitted>
  <last_update_submitted_qc>December 14, 2019</last_update_submitted_qc>
  <last_update_posted type="Actual">December 17, 2019</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <keyword>Assay</keyword>
  <keyword>Infection</keyword>
  <keyword>Direct Skin Feed</keyword>
  <keyword>Midgut</keyword>
  <keyword>Parasite</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Malaria</mesh_term>
  </condition_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT02206451
org study id: 999914159
secondary id: 14-I-N159
nct id: NCT02206451
lead sponsor: 
Background:

      - Malaria is a disease that affects many people in Mali and in Africa. It is caused by germs
      that are spread by mosquito bites. Researchers are creating vaccines that they hope will
      prevent malaria infection and/or the spread of it.

      Objective:

      - To test if the PfSPZ vaccine can stop malaria spread by mosquitoes.

      Eligibility:

      - People currently enrolled in the ongoing PfSPZ malaria vaccine trial. Participants must be
      willing to have uninfected mosquitoes bite them.

      Design:

        -  Participants will be able to take part in this study at every visit after receiving all
           scheduled vaccinations.

        -  Participants will be asked whether they are willing to participate in the procedures.
           Female participants will have a pregnancy test.

        -  Researchers will put about 60 mosquitoes in 2 or 3 cups (20 or 30 in each cup). They
           will hold each cup to the participant s leg or arm so the mosquitoes can bite. These
           mosquitoes do not carry germs and will take about 3 drops of blood total.

        -  Participants will get a cream for any swelling or itching.

        -  Participants will be checked the next day for any discomfort.

        -  Participants may take part in this feeding test multiple times, if they are willing.

        -  If participants have malaria parasites in their blood, they may be asked to take part in
           another study. For this, they will sleep alone in their hut the night after the feeding
           test. A study team will set up nets to collect mosquitoes that may have bitten the
           participant overnight.
A vaccine which interrupts malaria transmission (VIMT) is a critical tool to achieve the
      ultimate goal of eradication of this disease. VIMTs work by inducing humoral responses in
      vaccinated individuals that inhibit the development of malaria parasites in the mosquito, and
      combined humoral and cellular responses that inhibit the establishment of infection in
      humans. Overall efficacy of these vaccines is evaluated by measuring reduction of infection
      and clinical cases among vaccinees and the parasite infectivity to mosquitoes,
      (human-to-mosquito transmissibility), before and after vaccination, and with or without
      vaccination. One of the candidate VIMTs, the PfSPZ Vaccine, is currently being tested in Mali
      for safety, tolerance, and immunogenicity.

      The objective of this Feeding Assay Protocol is to explore the effect of the PfSPZ Vaccine,
      on interrupting human-to-mosquito transmission. Individuals from the the PfSPZ Vaccine trial
      in 2014 who also consent to be enrolled in this Feeding Assay Protocol will be eligible to
      participate in procedures including direct skin feeds (DSF) and experimental huts (EH). The
      human-to-mosquito transmission will be evaluated by examining the presence of malaria
      parasites in the midgut of mosquitoes fed on study participants. The human-to-mosquito
      transmission by DSF and EH assay methods will be analyzed for potential correlation.
observational model: Case-Only
time perspective: Prospective
measure: Measurement of infection/infectivity incidences
time frame: 1 year
measure: Measurement of infection intensity for a given mosquito that was fed on a given subject
time frame: 1 year
criteria: 
gender: All
minimum age: 18 Years
maximum age: 35 Years
healthy volunteers: Accepts Healthy Volunteers
last name: Sara A Healy, M.D.
role: Principal Investigator
affiliation: National Institute of Allergy and Infectious Diseases (NIAID)
facility: 
country: Mali
citation: Diallo M, Toure AM, Traore SF, Niare O, Kassambara L, Konare A, Coulibaly M, Bagayogo M, Beier JC, Sakai RK, Toure YT, Doumbo OK. Evaluation and optimization of membrane feeding compared to direct feeding as an assay for infectivity. Malar J. 2008 Dec 2;7:248. doi: 10.1186/1475-2875-7-248.
PMID: 19055715
citation: Gouagna LC, Yao F, Yameogo B, Dabire RK, Ouedraogo JB. Comparison of field-based xenodiagnosis and direct membrane feeding assays for evaluating host infectiousness to malaria vector Anopheles gambiae. Acta Trop. 2014 Feb;130:131-9. doi: 10.1016/j.actatropica.2013.10.022. Epub 2013 Nov 18.
PMID: 24262642
citation: Moorthy VS, Newman RD, Duclos P, Okwo-Bele JM, Smith PG. Assessment of the RTS,S/AS01 malaria vaccine. Lancet Infect Dis. 2013 Apr;13(4):280-2. doi: 10.1016/S1473-3099(13)70047-1. Epub 2013 Mar 1. No abstract available.
PMID: 23454165
responsible party type: Sponsor
mesh term: Malaria