ClinicalTrials.gg
CompletedNCT04174560Updated Mar 6, 2025Results posted

Phase I Norovirus Challenge Model

A Phase 1 interventional study of Norovirus GII.4 Challenge Pool in Gastroenteritis Norovirus, sponsored by National Institute of Allergy and Infectious Diseases (NIAID). Completed at 1 site in United States. Open to participants aged 18 Years to 49 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-03-06.

Sponsored by National Institute of Allergy and Infectious Diseases (NIAID) · Phase 1, Interventional, and Basic science

Phase
Phase 1
Study type
Interventional
Enrollment
48
Allocation
Non-randomized
Ages
18 Years to 49 Years
Sex
All
01

Study summary

This is a safety and infectivity study of experimental human Norovirus genogroup GII.4 administered to 48 healthy non-pregnant adults, 18-49 years of age, negative for COVID-19 by antigen testing at the time of norovirus challenge. Subjects will be admitted to the Vaccine Research Center inpatient facility and challenged with a dose of human norovirus GII.4 challenge strain. The challenge study will be conducted in 3 cohorts of approximately 16 subjects each, 15 subjects will have a functional FUT-2 gene (secretor positive) and 1 subject will have a non-functional FUT-2 gene (non-secretor). Subjects in Cohort 1 will receive 3.5x10\^3 copies of norovirus, in Cohort 2 will receive 3.5x10\^4 copies of norovirus and in Cohort 3 will receive 3.5x10\^5 copies of norovirus. Based on the illness rate of subjects meeting the primary outcome measure in secretor - positive subjects of the initial cohort, the decision will be made with regards to dosing of the second and the third cohorts. Study duration is approximately 12-18 months with subject participation duration of 6-8 months. The primary objective of this study is to determine the optimal challenge dose of Norovirus GII.4 CIN-3 Batch No.: 01-16C3 to achieve illness in > / = 50% of subjects (illness is defined as norovirus infection determined by positive Polymerase Chain Reaction (PCR) and either: a) > / = 3 loose or liquid stools, in a 24-hour period, b) > / = 300 gm of loose or liquid stool in a 24-hour period or c) and/or any episode of vomiting), during the inpatient period.

Read the detailed description

This is a double-blind, safety and infectivity study of experimental human Norovirus genogroup GII.4 administered to 48 healthy non-pregnant adults, 18-49 years of age, negative for COVID-19 by antigen testing at the time of norovirus challenge. Subjects will be admitted to the Vaccine Research Center inpatient facility and challenged with a dose of human norovirus GII.4 challenge strain. The challenge study will be conducted in 3 cohorts of approximately 16 subjects each, 15 subjects will have a functional FUT-2 gene (secretor positive) and 1 subject will have a non-functional FUT-2 gene (non-secretor). Subjects in Cohort 1 will receive 3.5x10\^3 copies of norovirus, in Cohort 2 will receive 3.5x10\^4 copies of norovirus and in Cohort 3 will receive 3.5x10\^5 copies of norovirus. Based on the illness rate of subjects meeting the primary outcome measure in secretor - positive subjects of the initial cohort, the decision will be made with regards to dosing of the second and the third cohorts. Subjects will remain in the inpatient facility for at least four days following the challenge and assessed daily for clinical and virologic evidence of norovirus infection. After the discharge, subjects will return to the site for evaluation on Days 6, 15, 30, 45, and 60 post challenge. A final phone call will be performed at day 180 to obtain an interim medical history. Study duration is approximately 12-18 months with subject participation duration of 6-8 months. The primary objective of this study is to determine the optimal challenge dose of Norovirus GII.4 CIN-3 Batch No.: 01-16C3 to achieve illness in > / = 50% of subjects (illness is defined as norovirus infection determined by positive Polymerase Chain Reaction (PCR) and either: a) > / = 3 loose or liquid stools, in a 24-hour period, b) > / = 300 gm of loose or liquid stool in a 24-hour period or c) and/or any episode of vomiting), during the inpatient period. The secondary objectives are: 1) To evaluate the safety of the Norovirus GII.4 CIN-3 Batch No.: 01-16C3 challenge strain; 2) To determine the rate of infection at different challenge doses by detection of norovirus GII.4 in the stool using specific qRT-PCR and Anti-norovirus GII.4 serum IgG by Enzyme-Linked Immunnosorbent Assay (ELISA) (> / = 4-fold rise from baseline through Day 30); 3) To measure the severity of acute gastroenteritis; 4) To determine the quantity and duration of virus shedding in stool by qRT-PCR.

02

Conditions studied

  • Gastroenteritis Norovirus

Browse trials for

Keywords

  • Healthy Adults
  • Norovirus GII.4 CIN-3
  • Optimal Human Challenge Dose
03

In context

Gastroenteritis

237 studies on the registry are indexed under Gastroenteritis; 16 are open to participants now.

This study's enrollment of 48 is below the median of 136 across 164 interventional studies indexed under Gastroenteritis.

Browse Gastroenteritis studies →

Lead sponsor

National Institute of Allergy and Infectious Diseases (NIAID) is the lead sponsor of 2,446 studies on the registry; 179 are open to participants now.

Of its 405 completed or terminated interventional studies of FDA-regulated products, 302 (75%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 49 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Subject able to provide .
  2. Male or non-pregnant females between the ages of 18 and 49 years, inclusive.
  3. Women of must be using an acceptable method of for at least 30 days prior to enrollment through day 45 after receipt of challenge virus.

    • A woman is considered of childbearing potential unless (absence of menses for > / = 1 year) or surgically sterilized (tubal ligation, bilateral oophorectomy or hysterectomy).
    • Acceptable contraception methods for women include but are not limited to: sexual abstinence from intercourse with men, monogamous relationship with vasectomized partner who has been vasectomized for 6 months or more prior to the subject enrolling in the study, barrier methods such as condoms or diaphragms with spermicide or foam, effective devices (intrauterine devices (IUD's), NuvaRing (R)) or licensed hormonal products such as implants, injectables or oral contraceptives.
  4. For women of childbearing potential, must have a negative serum or urine pregnancy test at screening.
  5. Are in good general health*.

    *As determined by medical history and physical examination to evaluate acute or currently ongoing chronic medical diagnoses or conditions, defined as those that have been present for at least 90 days, which would affect the assessment of the safety of subjects. Chronic medical diagnoses or conditions should be stable for the last 60 days (no hospitalizations, Emergency Room (ER), or urgent care for condition and no adverse symptoms that need medical intervention such as medication change/supplemental oxygen). This includes no change in chronic prescription medication, dose, or frequency as a result of deterioration of the chronic medical diagnosis or condition in the 60 days prior to enrollment. Any prescription change that is due to change of health care provider, insurance company, etc., or that is done for financial reasons, as long as in the same class of medication, will not be considered a deviation of this inclusion criterion. Any change in prescription medication due to improvement of a disease outcome, as determined by the site principal investigator or appropriate sub-investigator, will not be considered a deviation of this inclusion criterion. Subjects may be on chronic or as needed (prn) medications if, in the opinion of the site principal investigator or appropriate sub-investigator, they pose no additional risk to subject safety or assessment of reactogenicity and immunogenicity and do not indicate a worsening of medical diagnosis or condition. Similarly, medication changes subsequent to enrollment and study vaccination are acceptable provided there was no deterioration in the subject's chronic medical condition that necessitated a medication change, and there is no additional risk to the subject or interference with the evaluation of responses to study vaccination.

  6. Demonstrate knowledge and comprehension of the study by scoring > / = 70% on a quiz (test of understanding) of the study protocol and policies.
  7. Willing and able to participate in all study visits, including an inpatient stay of at least 96 hours.

Exclusion criteria

Exclusion Criteria:

  1. Have household contact with or have daily contact with children less than 2 years of age or persons older than 70 years of age.
  2. Have expected extended social contact (> 2 hours/day) with individuals in the 8 weeks after challenge*.

    *Including persons with infection or active cancer, children \<2 years of age, pregnant women or persons who are immunosuppressed (e.g. history of stem cell or organ transplantation) and/or provide any child day care services (in-home or non-residential facility).

  3. Are healthcare workers with direct patient contact or any child day care services (in-home or non-residential facility) in the 8 weeks after challenge.
  4. Are positive for COVID-19 by an antigen test at the time of admission to the challenge unit.
  5. Are food service workers expected to prepare/handle food in the 8 weeks after challenge.
  6. Plan to be living in a confined communal environment (e.g. ship, camp, or dormitory) within 8 weeks after receiving the challenge strain.
  7. For females, are pregnant or plan to become pregnant at any time between the Screening Visit through 45 days after receipt of the challenge virus.
  8. Are breastfeeding or plan to breastfeed at any given time throughout the study.
  9. Have a history of acute gastroenteritis in the 4 weeks prior to challenge or any history of chronic or recurrent diarrhea or vomiting.
  10. History of significant GI condition. *

    *Including: malabsorption, major GI surgery, current *eating disorder, irritable bowel syndrome, or any GI disorder (deemed by study physician) making it unsafe to participate.

  11. Have significant acute illness or an oral temperature > /= 100.4 degrees Fahrenheit within seven days prior to challenge.
  12. Have a heart rate \<45 beats per minute (bpm) or >100 bpm*.

    *If heart rate is \<45 beats per minute and the investigator determines that this is not clinically significant (e.g., athletes) and heart rate increases > 45 beats per minute on moderate exercise (two flights of stairs), subject will not be excluded. If a subject has significant abnormalities in their heart rate, they will be informed of the values and advised to seek care from their physician.

  13. Systolic blood pressure less than 90 mm Hg or greater than 150 mm Hg on two separate measurements (screening and baseline prior to challenge)*.

    *If a subject has significant abnormalities in their blood pressure, they will be informed of the values and advised to seek care from their physician.

  14. Diastolic blood pressure less than 50 mm Hg or greater than 90 mm Hg on two separate measurements (screening and baseline, prior to challenge).
  15. Have long-term use (> / = 2 weeks) of high-dose oral (> / = 20 mg per day prednisone or equivalent) or parenteral , or high-dose inhaled steroids for greater than 7 days in the last 6 months.
  16. Have an , inflammatory, vasculitic or rheumatic disease, including but not limited to systemic lupus erythematosus, polymyalgia rheumatica, rheumatoid arthritis or scleroderma.
  17. Have HIV, , or *.

    *Subjects will be tested for HIV, Hepatitis B surface antigen, and antibody to Hepatitis C at screening only. Any subjects having HIV, Hepatitis B, Hepatitis C infection will not be enrolled into the study.

  18. Have a seizure disorder.
  19. Have an active or history of malignancy* or current use of immunosuppressive or cytotoxic therapy.

    *Excluding nonmelanotic skin cancer in remission without treatment for more than 5 years.

  20. Have abnormal screening laboratory test results per laboratory reported normal values*.

    *For white blood cells (WBCs), (Hgb), , (ANC), total , potassium, sodium, and urine protein.

  21. Serum creatinine greater than a Grade 1 adverse event on enrollment.
  22. (ALT), greater than Grade 1 adverse event on enrollment.
  23. Have a chronic condition that the study physician feels would pose a threat to participating subjects*.

    *Including, but not limited to solid organ or stem cell transplantation, diabetes, clinically significant history of immunosuppressive illness, gall bladder disease, heart disease, lung disease, pancreatic disease, renal disease or neurological disease.

  24. Have ongoing drug abuse/dependence (including alcohol), or a history of these issues within 5 years of enrollment.
  25. Have a positive urine test for opiates.
  26. Have any medical, psychiatric, occupational, or behavioral problems that make it unlikely for the subject to comply with the protocol as determined by the investigator.
  27. Are unwilling to comply with study procedures including abstaining from smoking for the duration of the inpatient portion of the study.
  28. Have participated in a previous norovirus (NoV) challenge study or NoV vaccine study.
  29. Have received experimental products within 30 days before study entry or plan to receive experimental products at any time during the study.
  30. Plans to enroll in another clinical trial that could interfere with safety assessment of the product at any time during the study period*.

    *Including study interventions such as drugs, biologics or devices.

  31. Plan to donate blood during the course of the study.
  32. Have received a within 30 days before study entry or plan to receive a live vaccine prior to Day 30 of the study.
  33. Have received, or plan to receive, an inactivated vaccine within 14 days of challenge to 14 days after challenge.
  34. Received parenteral immunoglobulin or blood products within 3 months of challenge, or plan to receive parenteral immunoglobulin/blood products within 3 months after challenge.
  35. Use of antibiotics within 7 days prior to entry into the inpatient facility.
  36. Use of prescription and OTC medications containing acetaminophen, aspirin, ibuprofen, and other non-steroidal anti-inflammatory drugs within 48 hours prior to NoV challenge.
  37. Regular use of laxatives or anti-motility agents.
  38. Have a history of allergy to sodium bicarbonate.
  39. Have had a recent norovirus infection or have ever had a norovirus vaccine.
Terms in these criteria, in plain language(19)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

Absolute neutrophil count (ANC)

The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.

It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Live vaccines

Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.

05

Study design

Phase
Phase 1
Primary purpose
Basic science
Allocation
Non-randomized
Intervention model
Sequential assignment
Masking
Triple (Participant, Investigator, Outcomes assessor)
Enrollment
48 participants (actual)

Study arms

  • Experimental
    Cohort 1

    Single dose (3.5x10\^3 copies) of norovirus GII.4 CIN-3 Batch No.: 01-16C3 inoculum (with 60 mL of a 2% sodium bicarbonate before and after inoculum administration) will be given orally to subjects with functional FUT-2 gene (secretor positive), n=15, and single dose (3.5x10\^3 copies) of norovirus GII.4 CIN-3 Batch No.: 01-16C3 inoculum (with 60 mL of a 2% sodium bicarbonate before and after inoculum administration) will be given to subjects with a lack a non-functional FUT-2 gene (non-secretor), n=1, on Day 1

    Biological: Norovirus GII.4 Challenge Pool

  • Experimental
    Cohort 2

    Single dose (3.5x10\^4 copies) of norovirus GII.4 CIN-3 Batch No.: 01-16C3 inoculum (with 60 mL of a 2% sodium bicarbonate before and after inoculum administration) will be given orally to subjects with functional FUT-2 gene (secretor positive), n=15, and single dose (3.5x10\^4 copies) of norovirus GII.4 CIN-3 Batch No.: 01-16C3 inoculum (with 60 mL of a 2% sodium bicarbonate before and after inoculum administration) will be given to subjects with a lack a non-functional FUT-2 gene (non-secretor), n=1, on Day 1

    Biological: Norovirus GII.4 Challenge Pool

  • Experimental
    Cohort 3

    Single dose (3.5x10\^5 copies) of norovirus GII.4 CIN-3 Batch No.: 01-16C3 inoculum (with 60 mL of a 2% sodium bicarbonate before and after inoculum administration) will be given orally to subjects with functional FUT-2 gene (secretor positive), n=15, and single dose (3.5x10\^5 copies) of norovirus GII.4 CIN-3 Batch No.: 01-16C3 inoculum (with 60 mL of a 2% sodium bicarbonate before and after inoculum administration) will be given to subjects with a lack a non-functional FUT-2 gene (non-secretor), n=1, on Day 1

    Biological: Norovirus GII.4 Challenge Pool

Interventions

  • BiologicalNorovirus GII.4 Challenge Pool

    Subjects will be NPO (nothing by mouth) for at least 90 minutes followed by ingestion of 60 mL of a 2% sodium bicarbonate solution by mouth. 2 minutes later, subjects will be administered Norovirus GII.4 CIN-3. Five minutes following administration of the challenge dose, subjects will be administered a 60 mL volume of a 2% sodium bicarbonate solution and then remain NPO for at least the next 90 minutes. Subjects will be observed during the 60 minutes after receipt of the challenge by a study team member to detect and treat any immediate adverse reactions.

06

What researchers measure

Primary outcomes

  1. The Occurrence of Norovirus-associated Illness in Secretor Positive Participants Through Day 4 After Challenge.

    Illness is defined as norovirus infection, determined by a positive PCR, and either a) = 3 loose or liquid stools in a 24-hour period, b) = 300 gm of loose or liquid stool in a 24-hour period, and/or c) any episode of vomiting.

    Time frame: Day 1 through Day 4

Secondary outcomes

  1. The Number of Participants With Solicited Adverse Events Through Day 10

    Systemic solicited adverse events were collected pre-challenge, post-challenge, and via memory aid through 5 days after discharge from the isolation facility and graded on a scale of 0 (absent), 1 (mild), 2 (moderate) and 3 (severe). Systemic events include headache, nausea, abdominal cramps/discomfort/pain, abdominal gurgling, abdominal bloating, myalgia, malaise/fatigue, anorexia/loss of appetite, and chills.

    Time frame: Day 1 through Day 10

  2. The Number of Participants With Unsolicited Serious Adverse Events Reported Through Day 180.

    An adverse event or suspected adverse reaction is considered "serious" if, in the view of either the investigator or sponsor, it results in any of the following outcomes: death, a life-threatening adverse event, inpatient hospitalization or prolongation of existing hospitalization (excluding any extended stay during challenge admission due to continued vomiting, diarrhea, etc.), a persistent or significant incapacity of substantial disruption of the ability to conduct normal life functions, a congenital anomaly/birth defect, important medical events that may not result in death, be life-threatening, or require hospitalizations may be considered serious when, based upon appropriate medical judgment they may jeopardize the patient or participant and may require medical or surgical intervention to prevent one of the outcomes listed in this definition.

    Time frame: Day 1 through Day 180

  3. The Number of Participants With Unsolicited Grade 3 Adverse Events From Challenge to Day 30

    ICH E6 defines an AE as any untoward medical occurrence in a patient or clinical investigation participant administered a pharmaceutical product regardless of its causal relationship to the study treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of medicinal (investigational) product. The FDA defines an AE as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.

    Time frame: Day 1 through Day 30

  4. The Number of Participants With Infection Through Day 30

    Detection of norovirus GII.4 in stool by qRT-PCR at Days 2, 3, 4, 5, 6, 15, or 30; or \>/= 4-fold rise from baseline in GII.4-specific antibody titers in serum IgG by ELISA through Day 30

    Time frame: Day 1 through Day 30

  5. Peak Genome Equivalent Copies/mL of Virus in Stool as Measured by qRT-PCR After Challenge Through Day 60

    Peak virus in stool as measured by qRT-PCR \[genome equivalent copies per gram of stool (GEC/g)\] is the maximum GEC/g of all available stool samples tested post-challenge.

    Time frame: Day 1 through Day 60

  6. Duration (Number of Days) of Viral Secretion as Measured by qRT-PCR After Challenge Through Day 60

    Duration is based on the first and last days where norovirus is detected.

    Time frame: Day 1 through Day 60

  7. Modified Vesikari Score Through Day 4

    The score is made up of the following components: duration of diarrhea (days), maximum number of diarrheal stools per 24 hours, duration of vomiting (days), maximum number of vomiting episodes per 24 hours, fever, and dehydration. Each of the components will be assigned a point value and the points will be summed to create a total score out of a possible 17 for each participant, with 17 being the worst outcome, and 0 being a better outcome.

    Time frame: Day 1 through Day 4

  8. Duration (Hours) of Vomiting and/or Diarrhea Through Day 5

    The duration of diarrhea will be calculated for participants who had at least three stools classified as having loose or watery consistency, or who have at least two stools classified as having loose or watery consistency with \> 300 gm of loose or watery stools in a study day (from 00:00 to 23:59). The duration will be calculated as the interval between the first time a loose/watery stool is produced on a day the participant met the criteria for diarrhea through the last loose/watery stool on a day the participant met the criteria for diarrhea. The duration of vomiting during the inpatient period will be calculated for participants who had at least two episodes of vomiting in a study day or over two consecutive days. The duration of diarrhea and/or vomiting will be calculated beginning from the first diarrheal stool or episode of vomiting until the last diarrheal stool or episode of vomiting during the inpatient period.

    Time frame: Day 1 through Day 5

07

Results

Posted Nov 19, 2024

Participant flow

Participants were healthy non-pregnant adults, 18-49 years of age, inclusive. They were recruited from the community at large around the clinical site. Participants were enrolled between 28MAR2022 and 10JUL2023.

Participant flow — Overall Study
Milestone3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
Started1512183
Completed1412163
Not completed1020
Withdrew: Lost to follow-up1000
Withdrew: Withdrawal by subject0020

Outcome measures

PrimaryThe Occurrence of Norovirus-associated Illness in Secretor Positive Participants Through Day 4 After Challenge.

Illness is defined as norovirus infection, determined by a positive PCR, and either a) = 3 loose or liquid stools in a 24-hour period, b) = 300 gm of loose or liquid stool in a 24-hour period, and/or c) any episode of vomiting.

Time frame:
Day 1 through Day 4
Reported as:
Count of participants · Participants
The Occurrence of Norovirus-associated Illness in Secretor Positive Participants Through Day 4 After Challenge.
Participants3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
The Occurrence of Norovirus-associated Illness in Secretor Positive Participants Through Day 4 After Challenge.3270
SecondaryThe Number of Participants With Solicited Adverse Events Through Day 10

Systemic solicited adverse events were collected pre-challenge, post-challenge, and via memory aid through 5 days after discharge from the isolation facility and graded on a scale of 0 (absent), 1 (mild), 2 (moderate) and 3 (severe). Systemic events include headache, nausea, abdominal cramps/discomfort/pain, abdominal gurgling, abdominal bloating, myalgia, malaise/fatigue, anorexia/loss of appetite, and chills.

Time frame:
Day 1 through Day 10
Reported as:
Count of participants · Participants
The Number of Participants With Solicited Adverse Events Through Day 10
Participants3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
The Number of Participants With Solicited Adverse Events Through Day 101010153
SecondaryThe Number of Participants With Unsolicited Serious Adverse Events Reported Through Day 180.

An adverse event or suspected adverse reaction is considered "serious" if, in the view of either the investigator or sponsor, it results in any of the following outcomes: death, a life-threatening adverse event, inpatient hospitalization or prolongation of existing hospitalization (excluding any extended stay during challenge admission due to continued vomiting, diarrhea, etc.), a persistent or significant incapacity of substantial disruption of the ability to conduct normal life functions, a congenital anomaly/birth defect, important medical events that may not result in death, be life-threatening, or require hospitalizations may be considered serious when, based upon appropriate medical judgment they may jeopardize the patient or participant and may require medical or surgical intervention to prevent one of the outcomes listed in this definition.

Time frame:
Day 1 through Day 180
Reported as:
Count of participants · Participants
The Number of Participants With Unsolicited Serious Adverse Events Reported Through Day 180.
Participants3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
The Number of Participants With Unsolicited Serious Adverse Events Reported Through Day 180.0000
SecondaryThe Number of Participants With Unsolicited Grade 3 Adverse Events From Challenge to Day 30

ICH E6 defines an AE as any untoward medical occurrence in a patient or clinical investigation participant administered a pharmaceutical product regardless of its causal relationship to the study treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of medicinal (investigational) product. The FDA defines an AE as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related.

Time frame:
Day 1 through Day 30
Reported as:
Count of participants · Participants
The Number of Participants With Unsolicited Grade 3 Adverse Events From Challenge to Day 30
Participants3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
The Number of Participants With Unsolicited Grade 3 Adverse Events From Challenge to Day 300020
SecondaryThe Number of Participants With Infection Through Day 30

Detection of norovirus GII.4 in stool by qRT-PCR at Days 2, 3, 4, 5, 6, 15, or 30; or \>/= 4-fold rise from baseline in GII.4-specific antibody titers in serum IgG by ELISA through Day 30

Time frame:
Day 1 through Day 30
Reported as:
Count of participants · Participants
The Number of Participants With Infection Through Day 30
Participants3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
Detection of norovirus GII.4 in stool4490
>/= 4-fold rise in GII.4-specific antibody titers in serum IgG3491
Norovirus GII.4 in stool OR >/= 4-fold rise in GII.4-specific antibody titers in serum IgG45101
SecondaryPeak Genome Equivalent Copies/mL of Virus in Stool as Measured by qRT-PCR After Challenge Through Day 60

Peak virus in stool as measured by qRT-PCR \[genome equivalent copies per gram of stool (GEC/g)\] is the maximum GEC/g of all available stool samples tested post-challenge.

Time frame:
Day 1 through Day 60
Reported as:
Geometric mean · GEC/g
Peak Genome Equivalent Copies/mL of Virus in Stool as Measured by qRT-PCR After Challenge Through Day 60
GEC/g3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
Peak Genome Equivalent Copies/mL of Virus in Stool as Measured by qRT-PCR After Challenge Through Day 60230475280.31 (157130.618 to 338055406332)43569331.414 (156752.339 to 12110100882)176337339.33 (22259257.651 to 1396940442.9)—
SecondaryDuration (Number of Days) of Viral Secretion as Measured by qRT-PCR After Challenge Through Day 60

Duration is based on the first and last days where norovirus is detected.

Time frame:
Day 1 through Day 60
Reported as:
Mean · Days
Duration (Number of Days) of Viral Secretion as Measured by qRT-PCR After Challenge Through Day 60
Days3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
Duration (Number of Days) of Viral Secretion as Measured by qRT-PCR After Challenge Through Day 605 ± 2.79.8 ± 11.73.9 ± 1.5—
SecondaryModified Vesikari Score Through Day 4

The score is made up of the following components: duration of diarrhea (days), maximum number of diarrheal stools per 24 hours, duration of vomiting (days), maximum number of vomiting episodes per 24 hours, fever, and dehydration. Each of the components will be assigned a point value and the points will be summed to create a total score out of a possible 17 for each participant, with 17 being the worst outcome, and 0 being a better outcome.

Time frame:
Day 1 through Day 4
Reported as:
Mean · Points on a scale
Modified Vesikari Score Through Day 4
Points on a scale3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
Modified Vesikari Score Through Day 42.5 ± 2.33.1 ± 2.23.8 ± 3.22.7 ± 1.5
SecondaryDuration (Hours) of Vomiting and/or Diarrhea Through Day 5

The duration of diarrhea will be calculated for participants who had at least three stools classified as having loose or watery consistency, or who have at least two stools classified as having loose or watery consistency with \> 300 gm of loose or watery stools in a study day (from 00:00 to 23:59). The duration will be calculated as the interval between the first time a loose/watery stool is produced on a day the participant met the criteria for diarrhea through the last loose/watery stool on a day the participant met the criteria for diarrhea. The duration of vomiting during the inpatient period will be calculated for participants who had at least two episodes of vomiting in a study day or over two consecutive days. The duration of diarrhea and/or vomiting will be calculated beginning from the first diarrheal stool or episode of vomiting until the last diarrheal stool or episode of vomiting during the inpatient period.

Time frame:
Day 1 through Day 5
Reported as:
Mean · Hours
Duration (Hours) of Vomiting and/or Diarrhea Through Day 5
Hours3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
Duration of Diarrhea11.02 ± 5.7987.015 ± 4.92917.264 ± 15.32311.655 ± 8.733
Duration of Vomiting2.5 ± NA6.62 ± NA5.845 ± 7.646—
Duration of Diarrhea and/or Vomiting11.37 ± 6.2936.883 ± 3.49215.937 ± 13.3811.655 ± 8.733

Adverse events

Collected over Day 1 through Day 180. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
3.5x10^3 Copies - Secretor Positive0/15 (0%)0/15 (0%)11/15 (73.3%)
3.5x10^4 Copies - Secretor Positive0/12 (0%)0/12 (0%)11/12 (91.7%)
3.5x10^5 Copies - Secretor Positive0/18 (0%)0/18 (0%)15/18 (83.3%)
Secretor Negative0/3 (0%)0/3 (0%)3/3 (100%)
Most frequent other events
Showing 10 of 28
Most frequent other events
Event3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor Negative
MalaiseGeneral disorders5/159/129/182/3
Gastrointestinal Sounds AbnormalGastrointestinal disorders6/158/1213/181/3
Abdominal PainGastrointestinal disorders7/158/129/181/3
NauseaGastrointestinal disorders6/156/1211/180/3
HeadacheNervous system disorders7/156/1211/181/3
Abdominal DistensionGastrointestinal disorders6/157/127/181/3
ChillsGeneral disorders3/153/129/180/3
Decreased AppetiteMetabolism and nutrition disorders2/156/128/180/3
MyalgiaMusculoskeletal and connective tissue disorders3/154/128/180/3
TachycardiaCardiac disorders3/150/127/180/3

Baseline characteristics

Age, Continuous
Age, Continuous(years)3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor NegativeTotal
Mean37.4 ± 8.435.2 ± 7.735.3 ± 8.336.7 ± 8.536.0 ± 8.0
Sex: Female, Male
Sex: Female, Male(Participants)3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor NegativeTotal
Female5614126
Male1064222
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor NegativeTotal
Hispanic or Latino11002
Not Hispanic or Latino131118345
Unknown or Not Reported10001
Race (NIH/OMB)
Race (NIH/OMB)(Participants)3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor NegativeTotal
American Indian or Alaska Native00000
Asian00000
Native Hawaiian or Other Pacific Islander00000
Black or African American660315
White9518032
More than one race00000
Unknown or Not Reported01001
Region of Enrollment
Region of Enrollment(participants)3.5x10^3 Copies - Secretor Positive3.5x10^4 Copies - Secretor Positive3.5x10^5 Copies - Secretor PositiveSecretor NegativeTotal
United States151218348
08

Study locations

1 site
  • Cincinnati Children's Hospital Medical Center Vaccine Research Center
    Cincinnati, Ohio 45229-3039, United States
09

References and documents

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 6, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT04174560
Responsible party
Sponsor
First posted
Nov 22, 2019
Start date
Mar 28, 2022
Primary completion
Jul 13, 2023
Completion
Jan 8, 2024
Results posted
Nov 19, 2024
Last update
Mar 6, 2025

Oversight

FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Jan 2024. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion