Safety and Immunogenicity of a Human Hookworm Candidate Vaccine With or Without Additional Adjuvant in Brazilian Adults

Launched by BAYLOR COLLEGE OF MEDICINE · Dec 15, 2010

Keywords

ClinConnect Summary

Human hookworm infection is a soil-transmitted helminth infection caused by the nematode parasites Necator americanus and Ancylostoma duodenale. It is one of the most common chronic infections of humans, afflicting up to 740 million people in the developing nations of the tropics. The largest number of cases occurs in impoverished rural areas of sub-Saharan Africa, Southeast Asia, China, and the tropical regions of the Americas. Approximately 3.2 billion people are at risk for hookworm infection in these areas. N. americanus is the most common hookworm worldwide, whereas A. duodenale is mor...

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Males or females between 18 and 45 years, inclusive.
• • Good general health as determined by means of the screening procedure.
• • Available for the duration of the trial (42 weeks).
• • Willingness to participate in the study as evidenced by signing the informed consent document.
• • If found to be infected with hookworm during screening, has completed a course of three doses of albendazole.
• Exclusion Criteria:
• • Pregnancy as determined by a positive urine β-hCG (if female).
• • Participant unwilling to use reliable contraception methods up until one month following the third immunization (if female).
• • Currently lactating and breast-feeding (if female).
• • Inability to correctly answer all questions on the informed consent comprehension questionnaire.
• • Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, diabetes, or renal disease by history, physical examination, and/or laboratory studies.
• • Known or suspected immunodeficiency.
• • Laboratory evidence of liver disease (alanine aminotransferase \[ALT\] greater than 1.25-times the upper reference limit).
• • Laboratory evidence of renal disease (serum creatinine greater than 1.25-times the upper reference limit, or more than trace protein or blood on urine dipstick testing).
• • Laboratory evidence of hematologic disease (absolute leukocyte count \<3000/mm3 or \>12.5 x 103/mm3; hemoglobin \<10.3 g/dl or \<11.0 g/dl \[females in Americaninhas and Belo Horizonte, respectively\] or \<11.0 g/dl or \<12.0 \[males in Americaninhas and Belo Horizonte, respectively); absolute lymphocyte count \<900/mm3; or platelet count \<120,000/mm3).
• • Laboratory evidence of a coagulopathy (PTT or PT INR greater than 1.1-times the upper reference limit \[in Belo Horizonte\] or PT INR greater than 1.3 \[Americaninhas\]).
• • Serum glucose (random) greater than 1.2-times the upper reference limit.
• • Other condition that in the opinion of the investigator would jeopardize the safety or rights of a volunteer participating in the trial or would render the subject unable to comply with the protocol.
• • Participation in another investigational vaccine or drug trial within 30 days of starting this study.
• • Volunteer has had medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months.
• • History of a severe allergic reaction or anaphylaxis.
• • Severe asthma as defined by the need for regular use of inhalers or emergency clinic visit or hospitalization within the last 6 months.
• • Positive ELISA for HCV.
• • Positive ELISA for HBsAg.
• • Positive ELISA for HIV.
• • Use of corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 30 days of starting this study.
• • Receipt of a live vaccine within past 4 weeks or a killed vaccine within past 2 weeks prior to entry into the study.
• • History of a surgical splenectomy.
• • Receipt of blood products within the past 6 months.
• • History of allergy to yeast.
• • Anti-Na-GST-1 IgE antibody level above 0.35 kUA/L by the ImmunoCAP method.
• • For Part I only: history of previous infection with hookworm; residence for more than 6 months in a hookworm-endemic area; or, positive for hookworm infection on screening microscopic fecal examination.
• • For Part II only: previous receipt of a primary series of any hepatitis B vaccine.

Trial Officials