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Hookworm InfectionNCT00939198

Prevalence of Hookworm Infection and Community Preparedness for Hookworm Vaccine Trials in Endemic Areas of Brazil

A study testing Na-ASP-2 Skin Test Reagent in people with Hookworm Infection, run by Albert B. Sabin Vaccine Institute at 1 site in Brazil.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Na-ASP-2 is a protein expressed during the larval stage of the N. americanus hookworm life cycle. In a clinical study in previously hookworm-infected adults in Brazil, this protein induced urticarial reactions (rash) in a subset of volunteers. Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Hookworm Infection
What is being tested?
Na-ASP-2 Skin Test Reagent
Could I receive a placebo?
No, everyone receives an active treatment
How many people
87 participants
Where
1 siteBrazil
Study dates
Aug 2009to Dec 2012
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Males and females between 6 and 45 years of age, inclusive, at the time of consenting to the parent study.
  • Age greater than or equal to 18 years at the time of signing the supplemental informed consent document for the skin test procedure (parent study).
  • Willingness to participate in the study as evidenced by signing the informed consent or assent document.

Who cannot join

  • Inability to correctly answer all questions on the informed consent comprehension questionnaire.
  • Attends school or works full-time outside of the study area.
  • Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the volunteer to understand and cooperate with the study protocol.
  • Other condition that in the opinion of the investigator would jeopardize the safety or rights of a volunteer to participate in the trial or would render the subject unable to comply with the protocol.
  • Pregnancy as determined by a positive urine hCG test (if female).
  • Use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of planned skin test application.
Show all 9Show fewer
  • Extensive dermatitis precluding skin testing.
  • Current use of a beta blocker (oral or topical) or anti-histamine medication. A volunteer may participate in the study if they agree to withhold use of an anti-histamine for at least 5 days prior to application of the skin test.
  • Use of a tricyclic anti-depressant within the past month.

Trial locations and contacts

1 site in 1 country.

Brazil1 site
  • Centro de Pesquisas Rene Rachou

    Belo Horizonte, Minas Gerais

Other trials in Brazil

About this study

Official title: Determination of Prevalence and Intensity of Hookworm Infection and Community Preparedness for Hookworm Vaccine Trials in Endemic Areas of Northeastern Minas Gerais, Brazil

Na-ASP-2 is a protein expressed during the larval stage of the N. americanus hookworm life cycle. In a clinical study in previously hookworm-infected adults in Brazil, this protein induced urticarial reactions (rash) in a subset of volunteers. The clinical trial component of this study involves skin testing for immediate-type hypersensitivity to the Na-ASP-2 Antigen. Both prick-puncture and intradermal tests will be applied.

Read the detailed description

The clinical testing of the Na-ASP-2 Skin Test Reagent to detect Immediate-type hypersensitivity to the Na-ASP-2 hookworm antigen will be conducted as part of a larger, on-going observational study of the prevalence and intensity of hookworm infection currently underway in Brazil. Eligible adult participants (ages 18-45 years) in this observational study will be invited to undergo the skin testing procedure. Skin testing will only be performed if they agree and sign the supplemental informed consent form for this skin testing procedure.

  • Study site: Americaninhas Vaccine Center, Americaninhas, Minas Gerais, Brazil
  • Number of participants to be skin tested: approximately 150 adults
  • Duration of the skin testing procedures: up to 1 month; each participant will undergo skin testing and a follow-up blood collection 21+/-7 days after skin testing.
  • Each participant will have both skin prick-puncture and intradermal skin tests applied on the same study day. The prick-puncture and intradermal tests will be applied sequentially to the volar aspects of the participant's forearms:
  1. Skin prick-puncture: three different concentrations of Na-ASP-2 solution (10, 100, and 1000 μg/mL) will be applied sequentially in duplicate, to the left forearm.
  2. Intradermal: one concentration of Na-ASP-2 (100 μg/mL) will be injected, in duplicate, to the right forearm.
  3. Allergen diluent and histamine solutions will be utilized as the negative and positive controls, respectively, for both the skin prick-puncture and intradermal tests.
  4. Participants will be observed in the study clinic for at least 30 minutes following application of the skin tests, and will be examined 2 and 7 days following skin testing.
  5. Sizes of the wheal and erythema reactions for each application will be recorded and graded in comparison to the histamine positive control reaction.
  • Each participant will have blood collected via venipuncture (a maximum of 25 mL) immediately prior to application of the skin tests, and between 2 and 4 weeks after skin testing, in order to measure antibodies (particularly IgG and IgE) to Na-ASP-2 using an ELISA procedure.
Being tested
Na-ASP-2 Skin Test Reagent
Keywords
Hookworm, Allergy, Vaccine, Skin Test, Immediate-type hypersensitivity to Na-ASP-2 hookworm antigen
Medical subject headings
Hookworm Infections, Ancylostomiasis, Hypersensitivity

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Na-ASP-2 Skin Test ReagentBiological

    Na-ASP-2 Hookworm Skin Test Reagent, 1-1000 mcg/mL solution

Study groups in NCT00939198
Study groupRoleWhat they receive
Na-ASP-2 Hookworm Antigen Skin TestExperimentalAll participants will be skin tested with Na-ASP-2 skin test reagent applied to their arms, using both the prick-puncture and intradermal techniques.
Receives: Biological: Na-ASP-2 Skin Test Reagent

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Size of Wheal Diameter at Site of Skin Test Application, Measured 15 Minutes After Injection

    Measured: 15 minutes after skin test application

Secondary outcomes (1)
  1. Anti-Na-ASP-2 IgE Antibody Level on Day of Skin Test Reaction

    Measured: Upon skin testing

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 Jul 2009 (estimated)
  2. Study startAug 2009
  3. Primary completionJan 2012
  4. Study completionDec 2012

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Diagnosis
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
87 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00939198
Sponsor's protocol ID
SVI-06-01
Status last verified
Jul 2018
First submitted
13 Jul 2009
Last updated
1 Aug 2018
Data monitoring committee
No

Publications

  • Fujiwara RT, Bethony J, Bueno LL, Wang Y, Ahn SY, Samuel A, Bottazzi ME, Hotez P, Mendez S. Immunogenicity of the hookworm Na-ASP-2 vaccine candidate: characterization of humoral and cellular responses after vaccination in the Sprague Dawley rat. Hum Vaccin. 2005 May-Jun;1(3):123-8. doi: 10.4161/hv.1.3.1924. Epub 2005 May 20.

    PubMed 17012856
  • Goud GN, Bottazzi ME, Zhan B, Mendez S, Deumic V, Plieskatt J, Liu S, Wang Y, Bueno L, Fujiwara R, Samuel A, Ahn SY, Solanki M, Asojo OA, Wang J, Bethony JM, Loukas A, Roy M, Hotez PJ. Expression of the Necator americanus hookworm larval antigen Na-ASP-2 in Pichia pastoris and purification of the recombinant protein for use in human clinical trials. Vaccine. 2005 Sep 15;23(39):4754-64. doi: 10.1016/j.vaccine.2005.04.040.

    PubMed 16054275
  • Diemert DJ, Bethony JM, Hotez PJ. Hookworm vaccines. Clin Infect Dis. 2008 Jan 15;46(2):282-8. doi: 10.1086/524070.

    PubMed 18171264

Questions about this trial

What is this clinical trial studying?

A study testing Na-ASP-2 Skin Test Reagent in people with Hookworm Infection, run by Albert B. Sabin Vaccine Institute at 1 site in Brazil.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 1 Aug 2018. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 1 Aug 2018). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Size of Wheal Diameter at Site of Skin Test Application, Measured 15 Minutes After Injection (time frame: 15 minutes after skin test application). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00939198, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Aug 2018.

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