Influenza

64

Review clinical trials related to Influenza. Use filters to narrow results by trial status, phase, treatment, biological sex and sponsor.

Condition / disease
Location
Status: Recruiting

BPL-1357 Against H1N1 Influenza Virus Challenge

Background: Influenza (flu) infections are a serious global health threat. Each year, between 3 and 5 million people get the flu, and up to 500,000 die from it. Current vaccines protect against seasonal flus, but broader vaccines are needed to protect against potential flu pandemics. Objective: To test an experimental flu vaccine. Eligibility: Healthy people aged 18 to 55 years. Design: The study will last 5 to 8 months and has 2 phases, A and B. The study vaccine will be given either as a shot in the arm or as a nasal spray. Participants will receive 1 of 3 combinations: (1) study vaccine in the nose and placebo in the arm; (2) placebo in the nose and study vaccine in the arm; or (3) placebo in the nose and placebo in the arm. A placebo is just like the real vaccine but contains no active ingredients. Phase A: Participants will have 5 clinic visits over 56 days. They will receive a shot and a nasal spray at 2 of the visits, 28 days apart. At each visit, they will have a physical exam, with tests of their blood, urine, and nasal secretions. They will check their temperature at home and record any symptoms for 7 days after each vaccine. Phase B: Participants will stay in the hospital for at least 9 days. They will be infected with a flu virus. They will provide blood, urine, and nasal fluid samples. They will have tests of their heart function. They will remain in the hospital until they test negative for the flu 2 days in a row. They will have 2 follow-up visits, 4 and 8 weeks after leaving the hospital. ...

Participants needed: 129
Trial details
Phase: Phase 2Age: 18-55Biological sex: AllType: InterventionalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: Jul 13, 2026Locations: 2
Eligibility criteria

Adults >=18 and <= 55 years of age at the time of consent. [+22]

Chronic pulmonary disease (e.g., asthma, emphysema). [+26]

Status: Recruiting

BPL-1357 Against H1N1 Influenza Virus Challenge

Background: Influenza (flu) infections are a serious global health threat. Each year, between 3 and 5 million people get the flu, and up to 500,000 die from it. Current vaccines protect against seasonal flus, but broader vaccines are needed to protect against potential flu pandemics. Objective: To test an experimental flu vaccine. Eligibility: Healthy people aged 18 to 55 years. Design: The study will last 5 to 8 months and has 2 phases, A and B. The study vaccine will be given either as a shot in the arm or as a nasal spray. Participants will receive 1 of 3 combinations: (1) study vaccine in the nose and placebo in the arm; (2) placebo in the nose and study vaccine in the arm; or (3) placebo in the nose and placebo in the arm. A placebo is just like the real vaccine but contains no active ingredients. Phase A: Participants will have 5 clinic visits over 56 days. They will receive a shot and a nasal spray at 2 of the visits, 28 days apart. At each visit, they will have a physical exam, with tests of their blood, urine, and nasal secretions. They will check their temperature at home and record any symptoms for 7 days after each vaccine. Phase B: Participants will stay in the hospital for at least 9 days. They will be infected with a flu virus. They will provide blood, urine, and nasal fluid samples. They will have tests of their heart function. They will remain in the hospital until they test negative for the flu 2 days in a row. They will have 2 follow-up visits, 4 and 8 weeks after leaving the hospital. ...

Participants needed: 129
Trial details
Phase: Phase 2Age: 18-55Biological sex: AllType: InterventionalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: Jul 2, 2026Locations: 2
Eligibility criteria

Adults >=18 and <= 55 years of age at the time of consent. [+22]

Chronic pulmonary disease (e.g., asthma, emphysema). [+26]

Status: Recruiting

Screening for LID Clinical Studies Unit Healthy Volunteer Protocols

Background: * The Laboratory of Infectious Diseases (LID) Clinical Studies Unit (CSU) enrolls healthy volunteers into clinical studies to study infectious diseases. * Viruses can be highly infectious and contagious. They cause considerable illness in the United States each year and a good example of this is influenza (the flu). The LID CSU performs clinical studies to learn about these viral infections and assist in the development of vaccines and treatments for the infections. These clinical studies include influenza "challenge studies" as well as natural history studies and phase I trials involving vaccines for viruses carried by mosquitos such as Zika or Dengue virus. * In influenza challenge studies studies, doctors expose a person to a flu virus. Then they study the flu through the body's natural healing process. This information will help to find better ways to prevent the flu and may also improve treatments for the flu. * Natural history studies and phase I trials of new vaccines are performed so the researchers can learn how some viral infections occur and if new vaccines are safe and potentially effective in preventing the infections. In some of these studies, participants experience insect bites with special clean (non-infected) insects (such as mosquitos) to better understand the role of insects in these infections. Objectives: \- To screen healthy volunteers for future CSU studies. Eligibility: \- Healthy people between the ages of 18 and 65 Design: * The 3- to 5-hour screening exam includes the following: * Medical history and physical exam * Standard blood tests including pregnancy, Hepatitis B and C, and HIV tests * Standard urine drug testing * Electrocardiogram (ECG) to test heart rhythm and function * Chest x-ray * Eligible volunteers are enrolled in the study for up to 1 year, until they take part in a CSU study or are found to be ineligible to participate. * Volunteers may withdraw from the study pool at any time.

Participants needed: 5,000
Trial details
Age: 18-65Biological sex: AllType: ObservationalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: Jun 30, 2026Locations: 1
Eligibility criteria

Greater than or equal to 18 and less than or equal to 65 years old, and have no... [+3]

Chronic pulmonary disease (such as asthma, emphysema) [+6]

Status: Recruiting

Observational Digital Biomarker Discovery in Respiratory Virus Challenge Studies

Background: Respiratory viruses circulate throughout the year and around the globe. Wearable and sensor devices, like smartwatches, may be able to help monitor infectious diseases. Researchers want to use them to learn how respiratory viruses affect people in different ways. Objective: To use digital devices to collect data from participants in challenge studies that could indicate subtle changes in health during an infection that might otherwise go unnoticed. Eligibility: Healthy adults who have enrolled, were recently enrolled, or are scheduled to enroll in a challenge study. Design: Participants will stay at NIH for the duration of the challenge study (at least 9 days) and then will have outpatient follow-up visits (2-4). While at NIH, participants will wear a smartwatch at all times. It will record data like temperature, heart rate, breathing rate, and movements. Participants will have a smartphone that records at all times to listen for coughing and changes in voice. Participants will perform tasks every 4 hours during the daytime. They will record themselves coughing, breathing in deeply, and reading aloud. They will take videos of their face. They will play a game to test their reflexes and focus. They will measure their head temperature with their smartwatch. For outpatient visits, participants will use one smartphone and the smartwatch to complete the above tasks. Participants will be sent a smartwatch to wear at home at night to collect additional healthy data. Participation will last the duration of each challenge study, and may range from 10 weeks to 2 years.

Participants needed: 1,000
Trial details
Age: 18-65Biological sex: AllType: ObservationalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: Jun 18, 2026Locations: 1
Eligibility criteria

Able to provide informed consent. [+6]

Status: Recruiting

Safety and Pharmacokinetics of Ingavirin Forte, Capsules, 90 mg + 20 mg (Valenta Pharm JSC, Russia) Compared With Ingavirin, Capsules, 90 mg, Under Fasting and Fed Conditions.

This study aims to evaluate the safety and pharmacokinetic profile of the active ingredients Ingavirin forte, capsules, 90 mg + 20 mg (Valenta Pharm JSC, Russia) relative to single-entity Drug Ingavirin, capsules, 90 mg following administration under fasting and fed conditions.

Participants needed: 36
Trial details
Phase: Phase 1Age: 18-45Biological sex: AllType: InterventionalSponsor: Valenta Pharm JSCUpdated: Jun 12, 2026Locations: 1
Eligibility criteria

Voluntarily and personally signed Informed Consent Form (ICF) by a participant o... [+41]

Subject's decision to discontinue participation in the study; [+12]

Status: Not yet recruiting

Virological Surveillance of Acute Respiratory Infection in Primary Health Care in Metropolitan France

Every year in the fall and winter, numerous respiratory viruses (such as influenza viruses, SARS-CoV-2 (COVID-19), RSV, rhinovirus, and metapneumovirus) circulate in mainland France, causing acute respiratory infections (ARIs). These viruses can cause epidemics of varying severity, requiring close monitoring to determine their circulation levels and adapt public health measures accordingly. In France, ARI surveillance relies on two networks: the Sentinelles network in primary care and the RENAL network in hospitals. The Sentinelles surveillance is conducted in collaboration with Santé publique France, the National Reference Center for Respiratory Infection Viruses (Institut Pasteur and Hospices Civils de Lyon), and the University of Corsica. As part of the virological surveillance of ARIs, Sentinelles physicians are asked to collect nasopharyngeal swabs or saliva samples from a sample of patients presenting with an ARI during their clinic visits. This surveillance makes it possible to identify respiratory viruses circulating in primary care (general practice and pediatrics), to describe confirmed cases for each of the circulating viruses, and to estimate the impact of each on general practice. This surveillance also allows for the evaluation of the effectiveness of vaccines against influenza and COVID-19.

Participants needed: 25,000
Trial details
Biological sex: AllType: ObservationalSponsor: Institut National de la Santé Et de la Recherche Médicale, FranceUpdated: Jun 5, 2026Locations: 1
Eligibility criteria

be seen by a general practitioner or pediatrician participating in the Sentinell... [+3]

a person who is subject to a court-ordered protective measure; [+2]

Status: Not yet recruiting

Light-based Immunomodulation for Guarding Against Human Respiratory Tract Infections

The purpose of trial is to determine if daily usage of a photobiomodulation device will decrease the incidence of upper respiratory tract infections (URI) due to COVID, influenza or other viruses.The RD-X10 device is handheld, can be self-administered, and has been shown to be safe in invivo studies.

Participants needed: 130
Trial details
Age: 18+Biological sex: AllType: InterventionalSponsor: David MossUpdated: May 28, 2026
Eligibility criteria

Active Duty and DoD Beneficiaries (i.e. former military, spouse, dependent child...

Unable to comfortably insert RD-X19 into the mouth and keep in place for 5 minut... [+2]

Status: Recruiting

First-in-Human Study of VNT-101: Safety, Tolerability, and Pharmacokinetics

A randomized, double-blind, placebo-controlled Phase 1 study conducted at a single center with approximately 78 healthy adults aged 18-59 years. Part 1 Single Ascending Dose (SAD) will enroll 48 participants into six cohorts (S1-S6) to receive single oral doses of VNT-101 (100-1500 mg) or placebo under fasting or fed (S5 only) conditions. Part 2 Multiple Ascending Dose (MAD) will enroll 30 participants into three cohorts (M1-M3) to receive multiple oral doses of VNT-101 (250-750 mg BID Days 1-5, QD Day 6) or placebo under fasting conditions. Dose escalation in both parts will proceed after Protocol Safety Review Team (PSRT) review. The primary objective for Part 1 is to evaluate the safety and tolerability of single ascending oral (SAD) doses of VNT-101 in healthy adult participants under either fasting or fed conditions. The primary objective for part 2 is to evaluate the safety and tolerability of multiple ascending oral (MAD) doses of VNT-101 in healthy adult participants.

Participants needed: 78
Trial details
Phase: Phase 1Age: 18-59Biological sex: AllType: InterventionalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: May 11, 2026Locations: 1
Eligibility criteria

Provides written informed consent prior to the initiation of any trial procedure... [+16]

History or presence of clinically significant medical or psychiatric condition o... [+12]

Status: Recruiting

Enhancing Maternal Vaccine Knowledge and Uptake: The InTroDuce-Programme Trial

The goal of this InTroDuce-Programme interventional trial aims to test whether a web-based educational program can improve pregnant women's knowledge about Influenza and Tdap vaccinations and increase their intention to get vaccinated in the future. The main questions it aims to answer are: Does the InTroDuce-Programme increase knowledge and future intention of pregnant mothers to get vaccinated against Influenza and Tdap? How does demographic factors, attitudes and barriers affect vaccination decisions among pregnant mothers? Researchers will compare InTroDuce-Programme to standard care (routine antenatal care) to see if InTroDuce-Programme works to improve knowledge and future intention of pregnant mothers to be vaccinated against Influenza and Tdap. Participants will: Receive the web-based educational module (InTroDuce-Programme), which covers the importance, safety, and effectiveness of vaccinations, as well as addressing common concerns. Be followed up one month after the intervention. Answer questionnaires before and after the intervention to measure changes in vaccination knowledge and future intention to get vaccinated

Participants needed: 351
Trial details
Age: 18+Biological sex: FemaleType: InterventionalSponsor: Universiti Putra MalaysiaUpdated: May 1, 2026Locations: 4
Eligibility criteria

Pregnant women aged 18 years and older [+2]

Pregnant women with severe anaphylactic or allergic reactions to previous dose o... [+1]

Status: Recruiting

A Surveillance Study of Susceptibility to Baloxavir Marboxil in Pediatric Participants With Influenza and Transmission of Influenza to Household Contacts

This study consists of two parts: Part A Surveillance and Part B Transmission. The main purpose of Part A is to evaluate the prevalence of pre-dose and treatment-emergent amino acid substitutions in pediatric participants' \<12 years with influenza treated with baloxavir marboxil. Part B will include a subset of Part A participants who have household contacts (HHCs) recruited to the study. Part B will evaluate the incidence of onward influenza transmission from pediatric index participants (IPs) under 5 years of age and those aged 5 to under 12 years, treated with baloxavir marboxil, to their HHCs. Participants will no longer be enrolled to Part B Transmission as per protocol version 3.

Participants needed: 1,100
Trial details
Phase: Phase 3Age: 3-11Biological sex: AllType: InterventionalSponsor: Hoffmann-La RocheUpdated: May 1, 2026Locations: 51
Eligibility criteria

Participants with symptoms suggestive of influenza based on investigator's judge... [+14]

Participants with severe influenza virus infection requiring inpatient treatment [+10]

Status: Recruiting

Woodsmoke Exposure, Influenza Infection, and Nasal Immunity

This study will investigate the effects of woodsmoke (WS) exposure on human nasal mucosal immune responses to viral infection. The study tests the hypotheses that WS exposure modifies biomarkers of nasal mucosal immune function, increases in Live Attenuated Influenza Virus (LAIV) -induced nasal symptoms, and reduces mucosal antibody production.

Participants needed: 112
Trial details
Phase: Phase 4Age: 18-49Biological sex: AllType: InterventionalSponsor: University of North Carolina, Chapel HillUpdated: Apr 30, 2026Locations: 1
Eligibility criteria

Normal lung function, [+4]

A history of significant chronic illnesses (to include diabetes, autoimmune dise... [+9]

Status: Recruiting

High vs.Standard Dose Influenza Vaccine in Pediatric Solid Organ Transplant (SOT) Recipients

Influenza virus is a significant pathogen in pediatric solid organ transplant (SOT) recipients. However, these individuals respond poorly to standard-dose (SD) inactivated influenza vaccine (IIV). Recent studies have investigated two strategies to overcome poor immune responses in SOT recipients: (1) administration of high-dose (HD)-IIV compared to SD-IIV and (2) two doses of SD-IIV compared to one dose of SD-IIV in the same influenza season. One study compared HD-IIV vs. SD-IIV in adult SOT recipients and noted that HD-IIV was safe and more immunogenic; however, the median post-transplant period was 38 months. A phase I pediatric study comparing a single dose of HD-IIV vs. SD-IIV was safe with higher immunogenicity, but the study was limited by small sample size and median post-transplant vaccine administration was 26 months. In another phase II trial of adult SOT recipients, two doses of SD-IIV one month apart compared to one-dose of SD-IIV revealed modestly increased immunogenicity when given at a median of 18 months post-transplant. Therefore, these studies lack both evaluation in the early post-transplant period and substantive pediatric populations. Additionally, the administration of two-doses of HD-IIV in the same influenza season has not been evaluated in pediatric SOT recipients. Thus, the optimal immunization strategy for pediatric SOT recipients less than 24 months post-transplant is unknown. In addition, immunologic predictors and correlates of influenza vaccine immunogenicity in pediatric SOT recipients have not been well-defined. The central hypothesis of our proposal is that pediatric SOT recipients 1-23 months post-transplant who receive two doses of HD-quadrivalent inactivated influenza vaccine (QIV) will have similar safety but higher Hemagglutination Inhibition (HAI) geometric mean titers (GMTs) to influenza antigens compared to pediatric SOT recipients receiving two doses of SD-QIV.

Participants needed: 312
Trial details
Phase: Phase 2Age: 3-17Biological sex: AllType: InterventionalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: Apr 21, 2026Locations: 8
Eligibility criteria

Male or female, 3-17 years of age at time of enrollment [+5]

Inability (i.e. not able to understand and provide consent) or unwillingness of... [+8]

Status: Recruiting

GEneRating Mucosal Immunity After INfluenzA Infection and Vaccination in Lung and Lymphoid TissuE

This experimental medicine study aims to compare immune responses in healthy adult volunteers aged 18-55 years against influenza vaccination and infection in the upper and lower respiratory tract, following administration of a live-attenuated influenza vaccine delivered by nasal spray versus influenza A (H3N2) viral challenge.

Participants needed: 36
Trial details
Age: 18-55Biological sex: AllType: InterventionalSponsor: Imperial College LondonUpdated: Apr 20, 2026Locations: 1
Eligibility criteria

Adults aged between 18-55 years inclusive [+4]

History of clinically significant/currently active conditions; [+28]

Status: Recruiting

H5N1 Milk Detection Study

The purpose of this study is to determine whether drinking pasteurized milk (milk heated to kill harmful germs) that contains inactive particles of a flu virus called A(H5) could lead to the detection of the virus in the nose or throat. Inactive particles are not capable of causing disease. The results will help the Centers for Disease Control and Prevention (CDC) better understand how milk consumption could affect flu surveillance. Investigators also want to see if the body produces antibodies in response to this milk consumption.

Participants needed: 30
Trial details
Age: 18-64Biological sex: AllType: InterventionalSponsor: Emory UniversityUpdated: Apr 15, 2026Locations: 1
Eligibility criteria

Individuals aged 18-64 years [+3]

Symptoms of acute respiratory illness or conjunctivitis within 7 days [+8]

Status: Recruiting

A Phase 2 Trial Comparing Antiviral Treatments in Early Symptomatic Influenza

This trial will use a previously validated platform, to quantitatively assess antiviral effects in low-risk patients with high viral burdens and uncomplicated influenza, to determine in-vivo antiviral activity. In this randomised, open-label, controlled, group sequential, adaptive, platform trial, we will compare the performance of available influenza antivirals, and those with potential activity, relative to the control (no treatment) and each other. AD ASTRA study is supported by the Wellcome Trust Grant ref: 223195/Z/21/Z through the COVID-19 Therapeutics Accelerator

Participants needed: 3,000
Trial details
Phase: Phase 2Age: 18-60Biological sex: AllType: InterventionalSponsor: University of OxfordUpdated: Apr 14, 2026Locations: 4
Eligibility criteria

Patient understands the procedures and requirements and is willing and able to g... [+5]

Taking any concomitant medications or drugs which could interact with the study... [+14]

Status: Recruiting

The INFLUENTIAL Trial- Evaluation of National Inpatient Influenza Vaccination Program

This study plans to learn more about whether a stakeholder-informed, standardized inpatient vaccination program will increase influenza vaccination rates of hospitalized children across US pediatric health systems. The first part of the study is to form a multidisciplinary team of stakeholders, including parents, providers, nurses, pharmacists, informaticists, data analysts and communication experts across three sites in synthesizing a best practice implementation guide for an inpatient influenza vaccination program, which will then be piloted at these three sites.

Participants needed: 22,000
Trial details
Age: 6-99Biological sex: AllType: InterventionalSponsor: University of Colorado, DenverUpdated: Apr 8, 2026Locations: 2
Eligibility criteria

At least 6 months of age [+1]

At least 6 months of age [+1]

Status: Recruiting

Respiratory Virus Sampling and Repository

Background: Respiratory viruses, like the flu or COVID-19, cause significant illness and death worldwide. Researchers want to collect samples from people with respiratory virus infections. The samples in this natural history study will be used in future research. Objective: To obtain samples from people with respiratory viruses to learn more about respiratory virus infections and the immune responses against them. Eligibility: People aged 3 and older who have or are suspected to have a respiratory virus infection. Design: Participants will be screened with a medical record review. Participants will give blood samples. Data from their medical records will be collected. Participants will give nose samples. A soft plastic strip will be put into each nostril for a minute. They may also give nose, mouth (back of the throat), or saliva samples using swabs. Participants may receive kits by mail to collect nose and blood samples at home. They will use soft plastic strips to collect nose samples. To collect blood, they will prick their finger and dab a few drops of blood on four plastic tips. If a participant is in the hospital, air samples may be collected in their room. Participation will last for up to 2 years. After 2 years, participants may be asked for their consent again to give new samples and new medical data.

Participants needed: 20,000
Trial details
Age: 3+Biological sex: AllType: ObservationalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: Apr 8, 2026Locations: 2
Eligibility criteria

Aged 3 years or older. [+2]

Status: Recruiting

Natural History of Systemic and Nasal Mucosal Immunity to Influenza and SARS-CoV-2 in Adults After Vaccination

Background: Influenza (flu) vaccinations are required for all NIH staff members who have direct contact with patients. COVID-19 vaccines are recommended for persons 6 months of age and older. Researchers want to learn about immunity in NIH staff members who get a flu and/or COVID-19 vaccine. Objective: To understand what happens to the body s immune system throughout the year after getting the flu and/or COVID-19 vaccine. Eligibility: Adults ages 18 and older who work at NIH and plan to get the current season s flu vaccine and/or COVID-19 vaccine. Design: Participants will not get any vaccines as part of this study. Participants will be screened with a medical history and medicine review. They will get a survey via email. It will ask about their flu and SARS-CoV-2 history and vaccinations. Participants will have 12 monthly visits at NIH. If during that year they get both flu and SARS-COV-2 vaccines, their participation will be extended. Once a month, participants will be contacted. They will discuss any new medicines, recent vaccinations, or changes in medical history. Once a month, participants will have blood drawn. Once a month, participants will have nasal sampling. A small, flat absorptive strip will be placed in the nostril to soak up mucus. Participants will press against the outside of their nostril with their finger for 1 minute. Participants may be able to collect samples at home and mail them to NIH if they are not able to visit in person. Participation will last for about 12 13 months.

Participants needed: 150
Trial details
Age: 18-120Biological sex: AllType: ObservationalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: Apr 8, 2026Locations: 1
Eligibility criteria

NIH staff members, at the time of enrollment. [+5]

Already received the current season s influenza vaccine and does not plan to rec... [+3]

Status: Recruiting

A Study of mRNA-1018-H5 Pandemic Influenza Vaccine in Healthy Adults

The purpose of this study is to evaluate humoral immunogenicity after 2 doses of mRNA-1018-H5, and to evaluate the safety and reactogenicity of mRNA-1018-H5 in adults ≥18 years of age.

Participants needed: 4,000
Trial details
Phase: Phase 3Age: 18+Biological sex: AllType: InterventionalSponsor: ModernaTX, Inc.Updated: Apr 3, 2026Locations: 36
Eligibility criteria

Healthy as determined by medical evaluation including medical history; and physi... [+3]

Participant is acutely ill or febrile (body temperature ≥ 38.0 degrees Celsius [... [+10]

Status: Recruiting

pH1N1 Blinded Challenge Study

This protocol describes a clinical trial to develop and validate a Controlled Human Infection Model (CHIM) for influenza A/Arkansas/08/2020 (pH1N1). The study is designed to determine the optimal infectious dose of the pH1N1 challenge strain for use in future clinical trials evaluating influenza countermeasures. The study will enroll and challenge adult volunteers with the pH1N1 influenza virus challenge or sham inoculations. Given the adaptive design of this trial, the potential number of participants can vary. Depending on the pathway recommended by the PSRT and followed in the Trial Schema, the study population can range from around 30 to 99. The anticipated final sample size will be approximately 90 receiving pH1N1 challenge product plus and 6 persons receiving a sham inoculation. Participants will be pre-screened for health and for serological HAI antibody titers of \</1:40 against the challenge strain. Eligible participants will be enrolled sequentially into challenge cohorts and will be randomly assigned to receive a single dose of either sham inoculation or the interventional study product at a dose between 10\^6 to 10\^7 TCID50 (or 10\^5 TCID50 if needed). Dose titration will be conducted under an adaptive escalation schedule whereby dosing will start at 10\^6 TCID50 and escalate to the next dose if a pre-determined symptomatic influenza attack rate and clinical symptom score thresholds are not met and if the dose is determined to be safe with no pre-defined halting criteria being met. The primary objectives of this study are to determine the optimal infectious dose of a pH1N1 viral challenge to cause laboratory-confirmed clinical influenza and to assess the safety profile of pH1N1 viral challenge.

Participants needed: 90
Trial details
Phase: Phase 1Age: 18-55Biological sex: AllType: InterventionalSponsor: National Institute of Allergy and Infectious Diseases (NIAID)Updated: Apr 8, 2026Locations: 2
Eligibility criteria

Provides signed and dated informed consent form prior to the initiation of any t... [+4]

Able to take oral medication and willing to receive oseltamivir phosphate and/or... [+45]

Status: Not yet recruiting

Noseguard for Prevention of Respiratory Infections in Real-World Use

This study is a prospective clinical study to evaluate the effectiveness of combined use of two nasal protective medical devices (Noseguard and Noseguard Night) in reducing respiratory infection rates, including COVID-19 and influenza, in real-world conditions. The study will also assess usability, satisfaction, and safety using electronic patient-reported outcomes (ePRO).

Participants needed: 2,000
Trial details
Age: 19+Biological sex: AllType: InterventionalSponsor: Daewoong Pharmaceutical Co. LTD.Updated: Apr 8, 2026Locations: 1
Eligibility criteria

Adults aged ≥19 years [+1]

Hypersensitivity to device components [+3]

Status: Not yet recruiting

Phase 2a Study of the Efficacy and Safety of TRX-100 in a Human Influenza A Challenge Model

This will be a randomized, double-blind, placebo-controlled proof of concept study to evaluate the prophylactic efficacy and safety of orally administered TRX-100 in healthy adults challenged with influenza A/France/759/2021 (H1N1) virus.

Participants needed: 165
Trial details
Phase: Phase 2Age: 18-55Biological sex: AllType: InterventionalSponsor: Traws Pharma, Inc.Updated: Mar 31, 2026Locations: 1
Eligibility criteria

Written informed consent signed and dated by the participant and the PI/investig... [+9]

History of, or currently active, symptoms or signs suggestive of upper or lower... [+26]

Status: Recruiting

Influenza Human Challenge Model

This study examines how the immune system responds to the flu virus (H3N2) during and after infection and how the flu virus is transmitted in the environment. The study will used a flu virus called the H3N2 influenza challenge virus which was produced specifically for use in clinical research in controlled conditions. The study will also assess the safety of the H3N2 influenza challenge in healthy subjects. Mild to moderate symptoms are expected based on previous studies with this strain of influenza.

Participants needed: 80
Trial details
Phase: Phase 1Age: 18-49Biological sex: AllType: InterventionalSponsor: Emory UniversityUpdated: Mar 27, 2026Locations: 2
Eligibility criteria

Provide written informed consent prior to initiation of any study procedures. [+14]

Children under 5 years of age [+35]

Status: Recruiting

Influenza Vaccination Strategy for Patients With Hematologic Malignancy

This randomized controlled trial evaluates and compares the immunogenicity of three different influenza vaccine formulations: high-dose trivalent (HD-IIV3), MF59-adjuvanted quadrivalent (aIIV4), and standard-dose trivalent (SD-IIV3) vaccines. The study population consists of patients with hematologic malignancies, including those undergoing autologous stem cell transplantation or CAR-T cell therapy. The primary goal is to identify which vaccine strategy elicits the most robust antibody and T cell-mediated immune responses in this severely immunocompromised population

Participants needed: 60
Trial details
Phase: Phase 3Age: 19+Biological sex: AllType: InterventionalSponsor: Asan Medical CenterUpdated: Mar 24, 2026Locations: 1
Eligibility criteria

Adults aged 19 years or older

Difficulty with repeated venipuncture or blood sampling (e.g., poor vascular acc... [+4]

Status: Recruiting

Suraxavir Marboxil And Oseltamivir for Influenza Prophylaxis Under a Hospital-based Setting

This study aims to evaluate the efficacy of antiviral prophylaxis in preventing in-hospital influenza transmission. We will enroll hospitalized patients with confirmed influenza (index cases) and their uninfected roommates (room contacts). These room contacts will be randomized in a 1:1:1 ratio to one of three prophylactic groups: placebo, suraxavir marboxil, or oseltamivir. The primary outcome will be the rate of influenza infection among the room contacts, which will be monitored to determine the effectiveness of the interventions.

Participants needed: 384
Trial details
Phase: Phase 3Age: 12+Biological sex: AllType: InterventionalSponsor: Capital Medical UniversityUpdated: Mar 23, 2026Locations: 2
Eligibility criteria

The subject and/or their legal guardian agrees to participate in this clinical s... [+5]

Room contacts with a known allergy to the active ingredients or excipients of th... [+5]