ClinicalTrials.gg
Not yet recruitingNCT07342556EMIT-2b-1Updated Jan 15, 2026

Evaluating Modes of Influenza Transmission 2b Baseline SAR

An interventional study of Exposure to Donors with naturally acquired influenza virus infection in Influenza (Healthy Volunteers), sponsored by University of Maryland, College Park. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years to 49 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-15.

Sponsored by University of Maryland, College Park · Not applicable, Interventional, and Basic science

From the registry’s dates

  • Primary completion was expected by Mar 2026, 8 months ago, but the record still lists the study as not yet recruiting.
Phase
Not applicable
Study type
Interventional
Enrollment
80
Allocation
Not applicable
Ages
18 Years to 49 Years
Sex
All
01

Study summary

This is a research study to investigate how influenza transmits from person-to-person. Participation as a healthy "Recipient" in this study involves:

  • Home semi-quarantine lasting about 14 days during which the participants must wear an N95 in class and take other precautions
  • Daily assessments and clinic visits for 14 days
  • Spending every weekday evening for about 14 days from around 6 - 10 pm, including a provided dinner, in a controlled environment. There may be additional sessions and different required participation times on weekends
  • Exposure to people infected with influenza in the controlled environment
  • Three blood draws, at the start, at the end of 14 days, and about a month after the end.
  • A follow-up clinic visits one month after the end of home semi-quarantine
  • A two-month follow-up phone call. This study may increase the participant's risk of catching influenza.

If the participants get infected during the study, the investigators may:

  • Provide the participants with a prescription for antiviral medication or
  • Refer the participants for medical care
  • Ask the participants to become a Donor and expose other Recipients.

The participants will be compensated for their time and active participation in the study; however, they may not personally benefit from the study. While the participants may receive supportive care for an infection resulting from the study, this is not meant to replace their regular medical care. If the participants become very ill and need referral for medical care, they or their medical insurance will be billed.

If the participants are someone who recently became infected with influenza either through their daily activities or by participating in this study as a Recipient, they are invited to participate in this research study as a Donor and interact with a group of health participants in a controlled environment. Participation in this study as a Donor involves exposing Recipients for at least one and up to five days including:

  • Attend exposure events in a controlled environment

    • Weekday evenings from around 6-10 pm
    • Additional day and evening events on weekends
    • Events include a provided dinner
  • Daily assessments and clinic visits for 1 to 5 days
  • Provide exhaled breath samples for 30 to 60 minutes
  • Three blood draws, at the start and end of exposure events, and about a month after the end
  • A follow-up clinic visit one month after their last exposure event
  • A two-month follow-up phone call

If the participants experience severe symptoms related to their influenza infection, we may:

  • Provide the participants with a prescription for antiviral medication or
  • Refer the participants for medical care

The participants will be compensated for their time and active participation in the study; however, they may not personally benefit from the study. While the participants may receive supportive care for their influenza infection, this is not meant to replace their regular medical care. If the participants become very ill and need referral for medical care, they or their medical insurance will be billed.

02

Conditions studied

  • Influenza (Healthy Volunteers)

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Keywords

  • influenza
  • airborne transmission
  • infection transmission
  • touch transmission
  • spray (droplet) transmission
03

In context

Influenza, Human

2,356 studies on the registry are indexed under Influenza, Human; 184 are open to participants now.

This study's planned enrollment of 80 is below the median of 227 across 1,957 interventional studies indexed under Influenza, Human.

Browse Influenza, Human studies →

Lead sponsor

University of Maryland, College Park is the lead sponsor of 62 studies on the registry; 15 are open to participants now.

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

Eligibility criteria

Inclusion Criteria Recipients:

  1. Enrolled in the Recipient Registry (UMD IRB Protocol # 2303473, eligible age ≥18 and ≤49)
  2. Provides written , can comply with the planned study procedures, is available for an up to \~14-day home semi-quarantine period, and can attend scheduled exposure events and scheduled follow-up visits.
  3. Participants must be able to comprehend the study requirements, as evidenced by a score of 100% on the comprehension assessment (repeated tries permitted).
  4. No significant change (for the worse) in general health history or in concomitant medication use, as compared from their responses collected during screening (Recipient Protocol).
  5. Live in a private, single occupancy bedroom and agree to take precautions to avoid contracting a respiratory infection outside of the controlled exposure events through a home semi-quarantine prescribed by investigators.
  6. Agree not to meet with other participants (Recipients or Donors) outside of the programmed exposure events during their participation in the home semi-quarantine.

Exclusion Criteria Recipients:

  1. Female of who has a positive urine pregnancy test within 24 hours of enrollment in a Recipient Cohort or is breastfeeding or planning to become pregnant within 2 months after enrollment.
  2. Presence of infection with influenza, SARS-CoV-2, or other respiratory pathogens detected via a multiplex nucleic acid amplification test (e.g., TaqMan Array Card assay) at entry to the transmission trial.

    a. Volunteers with influenza infection may be eligible to enroll as Donors.

  3. Within the past 72 hours, presence of influenza-like illness, as defined as fever of ≥100.2°F AND cough or sore throat, in the absence of an alternative cause.
  4. Receipt of any blood products within the past 2 months.
  5. Does not agree to provide permission for secondary research use of extra samples collected and stored specimens.
  6. Habitual smoker of tobacco, marijuana, or e-cigarettes per self-report. (Habitual smokers are those who smoke or vape more than four cigarettes, other tobacco products, e-cigarettes or marijuana in a week for more than three months or use an inhaled nicotine or marijuana product more than 3 days a week on average. Edible or patch forms of tobacco or marijuana products do not constitute an exclusion.)
  7. Self-reported or known history of alcohol or drug abuse in the past two years and/or illicit drug use within the last 30 days. (Prescribed stimulants for the treatment of ADHD and cannabinoids use do not constitute exclusionary criteria)
  8. Has an ongoing symptomatic condition for which the individual has had or has ongoing medical investigations but has not yet received a diagnosis or treatment plan. (symptomatic condition means for example ongoing chronic fatigue without a diagnosis for symptom.)
  9. Presence of self-reported or medically documented significant medical or psychiatric condition(s) Significant medical or psychiatric conditions include but are not limited to:

    1. Respiratory disease (e.g., [COPD], asthma, cystic fibrosis) requiring daily medications* currently or any treatment of respiratory disease exacerbations or hospitalizations for acute respiratory illnesses (e.g., asthma exacerbation) in the last 5 years. (* Asthma medications: inhaled, oral, or intravenous (IV) , leukotriene modifiers, long and short acting beta agonists, theophylline, ipratropium, biologics.)
    2. Significant cardiovascular disease (e.g., congestive heart failure, cardiomyopathy, ischemic heart disease) or history of myocarditis or pericarditis as an adult.
    3. Neurological or neurodevelopmental conditions (e.g., epilepsy, stroke, seizures, encephalopathy, focal neurologic deficits, Guillain-Barré syndrome, encephalomyelitis or transverse myelitis).
    4. Ongoing or recent diagnosis of malignancy, including leukemia; treated, non-melanoma skin cancers are permissible.
    5. An disease.
    6. An immunodeficiency of any cause.
    7. A blood disorder (e.g., sickle cell disease)
    8. Endocrine disorders (e.g., diabetes)
    9. Liver, kidney, metabolic disorders
    10. ≥40 kg/m2
    11. Persistent post-viral syndromes with ongoing cardiovascular, respiratory, or neurologic conditions.
    12. Any other condition or behavior that in the opinion of the PI would affect the ability to participate in the screening or future transmission studies.
  10. Presence of or any medications that may be associated with impaired immune responsiveness. Including, but not limited to, corticosteroids exceeding 10 mg/day of prednisone equivalent, immunoglobulin, interferon, immunomodulators, cytotoxic drugs, or systemic corticosteroids or other similar or toxic drugs during the preceding 2-month period. Low dose topical and intranasal steroid preparations used for a discrete period are permitted.
  11. Known allergy or intolerance to treatments for influenza and other respiratory infections (including but not limited to oseltamivir, baloxavir, acetaminophen/paracetamol).
  12. History of a previous severe allergic reaction to medicines of any kind with generalized urticaria, angioedema, or anaphylaxis.
  13. Participating in any other interventional clinical trial that has a scheduled intervention 30 days prior to the start or after the end of the home semi-quarantine.

Inclusion Criteria Donors:

  1. Provides written informed consent, able to comply with the planned study procedures, available for between 1 and 5 days of multiple hour daily transmission experiments in a controlled environment research facility for the transmission trial and can attend the scheduled follow-up visits.
  2. Comprehends the study requirements, as evidenced by a score of 100% on the comprehension assessment (repeated tries permitted).
  3. Males and non-pregnant, non-breastfeeding females1 aged ≥18 and ≤59 years of age, at time of initial consent. Pregnancy and breastfeeding status to be determined by self-report.
  4. Agrees to the collection of specimens for secondary research.
  5. Evidence of onset of respiratory infection within the past 48 hours at time of entry into the Donor's initial exposure event, including one or more of the following:

    1. Onset of influenza-like illness, as defined as fever (measured oral temperature of ≥100.2°F or self-reported fever in the absence of a measured temperature) AND cough or sore throat in the setting of local influenza activity.
    2. Onset of less specific symptoms with a positive molecular test for influenza virus infection.
    3. Laboratory-confirmed influenza infection (including rapid antigen test in the setting of known local influenza activity) with significant exposure to a laboratory confirmed influenza case (e.g., a roommate) within the last 4 days in the absence of symptoms.

Exclusion Criteria Donors:

  1. Female of childbearing potential who is breastfeeding or has positive urine pregnancy test upon enrollment.
  2. Presence of self-reported or medically documented significant medical or psychiatric condition(s) Significant medical or psychiatric conditions include but are not limited to:

    1. Respiratory disease (e.g., chronic obstructive pulmonary disease [COPD], asthma, cystic fibrosis) requiring daily medications currently or any treatment of respiratory disease exacerbations or hospitalizations for acute respiratory illnesses (e.g., asthma exacerbation) in the last 5 years. Asthma medications: inhaled, oral, or intravenous (IV) corticosteroids, leukotriene modifiers, long and short acting beta agonists, theophylline, ipratropium, biologics.
    2. Significant cardiovascular disease (e.g., congestive heart failure, cardiomyopathy, ischemic heart disease) or history of myocarditis or pericarditis as an adult.
    3. Neurological or neurodevelopmental conditions (e.g., epilepsy, stroke, seizures, encephalopathy, focal neurologic deficits, Guillain-Barré syndrome, encephalomyelitis or transverse myelitis).
    4. Ongoing malignancy or recent diagnosis of malignancy, including leukemia; treated, non-melanoma skin cancers are permissible.
    5. An autoimmune disease.
    6. An immunodeficiency of any cause.
    7. A blood disorder (e.g., sickle cell disease)
    8. Endocrine disorders (e.g., diabetes)
    9. Liver, kidney, metabolic disorders
    10. BMI ≥40 kg/m2
    11. Persistent post-viral syndromes with ongoing cardiovascular, respiratory, or neurologic conditions.
    12. Any other condition or behavior that in the opinion of the PI would affect the ability to participate in the transmission study over the next several days.
    13. Meets criteria for escalation of care at the time of enrollment visit (will be referred for care).
  3. Presence of immunosuppression or any medications that may be associated with impaired immune responsiveness Including, but not limited to, corticosteroids exceeding 10 mg/day of prednisone equivalent, immunoglobulin, interferon, immunomodulators, cytotoxic drugs, or systemic corticosteroids or other similar or toxic drugs during the preceding 2-month period. Low dose topical and intranasal steroid preparations used for a discrete period are permitted.
  4. Ongoing symptomatic condition for which individual has had or has ongoing medical investigations but has not yet received a diagnosis or treatment plan.

    e.g., ongoing and debilitating fatigue without a diagnosis for the symptom.

  5. Self-reported or known history of alcohol or drug abuse within the past two years or illicit drug use within the last 30 days.
  6. Is a habitual smoker of tobacco, marijuana, or e-cigarettes per self-report. Habitual smokers are those who smoke or vape more than four cigarettes, other tobacco products, e-cigarettes or marijuana in a week for more than three months or use an inhaled nicotine or marijuana product more than 3 days a week on average. Edible or patch forms of tobacco or marijuana products do not constitute an exclusion.
  7. Known allergy or intolerance to treatments for influenza and other respiratory infections (including but not limited to acetaminophen/paracetamol).
  8. History of a previous severe allergic reaction to medicines of any kind with generalized urticaria, angioedema, or anaphylaxis.
  9. Presence of infection with SARS-CoV-2, as detected via a multiplex nucleic acid amplification test (e.g., Cepheid 4-Plex).
  10. Participating in any other interventional clinical research study that has a scheduled intervention 30 days prior to or after the transmission trial.
  11. Any condition, to include medical and psychiatric conditions, that in the opinion of the Investigator, might interfere with the safety of the participant or the study objectives.
Terms in these criteria, in plain language(8)

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.

COPD

Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.

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.

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.

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.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

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.

05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
80 participants (estimated)

Study arms

  • Other
    Exposure to Donors with naturally acquired influenza infection under controlled conditions

    Recipients are exposed to Donors in a controlled environment while performing prescribed activities, including playing cards and other games, and periodically shaking hands with Donors and rubbing their own nose and eyes.

    Other: Exposure to Donors with naturally acquired influenza virus infection

Interventions

  • OtherExposure to Donors with naturally acquired influenza virus infection

    Recipients are exposed to Donors in a controlled environment while performing prescribed activities, including playing cards and other games, and periodically shaking hands with Donors and rubbing their own nose and eyes.

06

What researchers measure

Primary outcomes

  1. PCR confirmed transmission of influenza virus infection

    Transmission of influenza infection defined as having \>1 nasal swab test positive for an influenza virus matching the type and subtype detected in a trial Donor.

    Time frame: 1 month

  2. Genomic sequencing-confirmed transmission of influenza virus infection

    Sequencing-confirmed transmission will be defined as a Recipient infection with a virus having ≤2 nucleotide difference from the virus infecting a trial Donor and closer genetic relationship to the apparent source Donor than Donors recruited from the community are to each other.

    Time frame: 1 month

  3. Culture-confirmed transmission of influenza virus infection

    Culture-confirmed transmission will be defined as positive viral culture for a virus that is also a sequence match to a virus cultured from a Donor.

    Time frame: 1 month

07

Study locations

1 site
08

References and documents

Publications

  • Nguyen-Van-Tam JS, Killingley B, Enstone J, Hewitt M, Pantelic J, Grantham ML, Bueno de Mesquita PJ, Lambkin-Williams R, Gilbert A, Mann A, Forni J, Noakes CJ, Levine MZ, Berman L, Lindstrom S, Cauchemez S, Bischoff W, Tellier R, Milton DK; EMIT Consortium. Minimal transmission in an influenza A (H3N2) human challenge-transmission model within a controlled exposure environment. PLoS Pathog. 2020 Jul 13;16(7):e1008704. doi: 10.1371/journal.ppat.1008704. eCollection 2020 Jul. PubMed 32658939 ↗
  • Lai J, Sobhani H, Coleman KK, Tai SS, Hong F, Sierra Maldonado I, Esparza Y, McPhaul KM, Zhu S, DeVoe DL, Ortiz JR, Chen S, Yellin T, Carreno JM, Krammer F, Cowling BJ, Gordon A, Chen WH, Srebric J, Milton DK; EMIT-2 Study Team. Evaluating modes of influenza transmission (EMIT-2): Insights from lack of transmission in a controlled transmission trial with naturally infected donors. PLoS Pathog. 2026 Jan 7;22(1):e1013153. doi: 10.1371/journal.ppat.1013153. eCollection 2026 Jan. PubMed 41499634 ↗

Individual participant data

Plan to share: Yes — De-identified participant data will be made available through appropirate repositories (e.g. OSF.io) using REDCap's de-identification options. REDCap is a HIPAA compliant data system which we will use to store data and distribute electronic informed consent forms and surveys. This system provides de-identification options that we can use to generate de-identified data by removing known identifier fields, invalidated text fields, notes fields, and/or date fields. We can also use it to shift date and/or hash record names so the actual values will be hidden.

Time frame: IPD will be made publicly available at the time of publication of study results and will be published in a permanent (to the extent that the internet is permanent) repository with permanent DOI.

Access criteria: Publicly available via a DOI included in publications.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Start is estimated for Jan 2026; primary completion for Mar 2026, 2 months later.

Of 146 non-industry interventional studies with no phase under Influenza, Human, half reached primary completion within 7 months of starting (the median), counting those still running; a quarter within 3 and three quarters within 18. This study's planned 2 months is below that.

Counting every sponsor, half of 166 studies reached it within 6 months; a quarter within 3 and three quarters within 16.

How these figures are worked out, and which studies are left out of them.

Registered
Jan 13, 2026
First posted
Jan 15, 2026
StartEst.
Jan 2026
Primary completionEst.
Mar 2026
CompletionEst.
May 2026
Last update
Jan 15, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jan 15, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07342556
Lead sponsor
University of Maryland, College Park
Responsible party
Donald K. Milton (Distinguished University Professor, University of Maryland, College Park) — Principal investigator
First posted
Jan 15, 2026
Start date
Jan 2026 (estimated)
Primary completion
Mar 2026 (estimated)
Completion
May 2026 (estimated)
Last update
Jan 15, 2026

Study contacts

Yi Esparza, MSN
Contact
yesparza@umd.edu
301-405-3142
Isabel Sierra Maldonado, MHA
Contact
itsierra@umd.edu
301-405-3142
Donald K Milton, MD, DrPH
principal investigator · University of Maryland School of Public Health

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.

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