Clinical Research Directory

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.

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. ...

Influenza Vaccine (Split Virion), Inactivated, Quadrivalent in Pregnant Women

This is a randomized, double-blind, positive controlled phase Ⅲ clinical trial to assess the immunogenicity and safety of Sinovac QIV in pregnant women. A total of 150 healthy pregnant women aged 18\~39 years at 20 to 32 weeks of pregnancy will be enrolled. All participants will be randomized to test group and control group in a ratio of 2:1 and receive one dose of vaccine (0.5 mL) of Sinovac QIV or Vaxigrip QIV, respectively. Blood samples will be collected from participants prior to vaccination and 28 days after vaccination. Moreover, to evaluate trans-placental antibodies, blood samples at the end of the gestation period (delivery) and the cord blood sample will be collected, if applicable. For safety assessment, any immediate adverse events within 30 minutes, solicited local and systemic adverse events within 7 days and unsolicited adverse events within 28 days will be collected. Serious adverse events will be collected within 8 weeks after delivery. Pregnancy and birth outcomes will be collected as well.

Comparative Immunogenicity of Respiratory Virus Vaccines (CIRV2) Study

CIRV2 is a Phase IV randomized, open-label, trial of FDA-approved COVID-19 and/or influenza vaccines (no more than minimal risk) with longitudinal follow-up. In 2026 CIRV2 will compare immunogenicity and reactogenicity of the recombinant Novavax COVID-19 vaccine and the mRNA Pfizer-BioNTech COVID-19 vaccine.

Clinical Outcomes and Pharmacotherapy Effectiveness in the VA Health Care System (COPE-VA)

The purpose of this study is to comprehensively describe the temporal and geographic utilization of COVID-19 therapies used for mild to moderate disease during different periods of SARS-CoV-2 variant circulation as well as to compare demographic and clinical characteristics of Veterans who are treated or do not receive these different therapies. The investigators will also perform similar descriptive epidemiology for other respiratory viruses, including RSV and influenza and other infectious diseases. This first phase will critically inform feasibility and direction of the second phase, in which the investigators will use target trial emulation design to study the comparative effectiveness of therapies and vaccines for COVID-19, respiratory viruses, including RSV, and influenza, and other infectious diseases.

Safety and Immunogenicity of Chimeric Hemagglutinin mRNA Vaccine Candidates

This is a Phase 1, randomized, controlled, dose-ranging clinical trial to assess the safety and immunogenicity of novel influenza A Group 1 and influenza A Group 2 mRNA chimeric hemagglutinin (HA) vaccine candidates given as intramuscular injections alone and in combination. A total of 60 healthy men and non-pregnant, non-breastfeeding women aged 18 through 59 years will be enrolled in one of 6 study arms. The 6 arms will consist of: 1) Sequential influenza A Group 1 mRNA chimeric hemagglutinin: cH8/1 (25 µg) followed by cH5/1 (25 µg), 2) Sequential influenza A Group 2 mRNA chimeric hemagglutinin: cH15/3 (25 µg) followed by cH4/3 (25 µg), 3) Sequential combined influenza A Group 1 and Group 2 mRNA chimeric hemagglutinin: cH8/1 + cH15/3 (25 µg) followed by cH5/1 + cH4/3 (25 µg), 4) A single dose of combined influenza A Group 1 and Group 2 mRNA chimeric hemagglutinin: cH8/1 + cH15/3 (50 µg) followed by placebo, 5) A single dose of combined influenza A Group 1 and Group 2 mRNA chimeric hemagglutinin: cH5/1 + cH4/3 (50 µg) followed by placebo, 6) Sequential combined influenza A Group 1 and Group 2 mRNA chimeric hemagglutinin: cH8/1 + cH15/3 (50 µg) followed by cH5/1 + cH4/3 (50 µg). The primary objectives are to evaluate safety and immunogenicity: 1) To assess the safety and reactogenicity of one or two doses of monovalent or bivalent Group 1 and 2 study products and 2) To describe the Group 1 and 2 anti-HA stalk IgG antibody responses of one or two doses of monovalent or bivalent Group 1 and 2 study products by ELISA.

A Study to Look at the Health Outcomes of Patients With COVID-19 and Influenza

The main purpose of this study is to understand: * the symptoms of COVID-19 or influenza- health-related outcomes of people with COVID-19 or influenza (influenza only included in updated study analyses) * the potential effects of COVID-19 vaccines in people with COVID-19 This study will enroll participants who are: * 18 years or older * reported to have symptoms with tests that have confirmed illness. The tests can be taken at any of CVS pharmacy COVID-19 or influenza test sites. The study will collect vaccine history information from participants who are ready to take part in the study. Participant will be emailed a form with questions about their health related to COVID-19 or influenza during multiple follow-ups over a 6-month period.

Cellular and Molecular Characterization of the Immune Response in Healthy NIH Employees atBaseline, and After Immunization With the H1N1 or Seasonal Influenza Vaccines

Background: \- Seasonal influenza is a major health problem whose impact is typically reduced by vaccination. The H1N1 (swine flu) influenza virus is an emerging pathogen that has the potential to cause devastating illness and even death in the coming months. Currently, there are limited data on the cellular and molecular immune responses in adult recipients of either the seasonal or the H1N1 influenza vaccines. Objectives: \- To obtain blood and nasal wash samples and perform laboratory studies to characterize the immune response in healthy adult volunteers at baseline and after immunization with the seasonal or H1N1 influenza vaccines. Eligibility: \- Adult employees at least 18 years of age of the NIH Clinical Center who are deemed healthy by a brief medical history and physical examination and routine blood testing. Design: * Before the start of the influenza season, volunteers will receive either the seasonal influenza vaccine or the H1N1 vaccine when it becomes available. If the H1N1 vaccine is available at the start of the season, volunteers will receive both the seasonal vaccine and the H1N1 vaccine. * Blood will be drawn over an 8-week period. Volunteers must not eat anything for 8 hours prior to the blood draw. The sequence of the blood draws is as follows: 2 weeks before vaccination; right before vaccination; and 1, 7, 14, 28, and 60 days after vaccination. * Two to four nasal washings will be collected by a nurse before volunteers receive the vaccination(s) and 28 days after the vaccination. * Prevaccine and postvaccine blood and nasal wash samples will be compared to determine volunteers immune responses. * Research samples will be stored indefinitely and will be used strictly for laboratory experiments.

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.

Information-Based Interventions for Influenza Vaccination Among Older Adults With Diabetes in Yangzhou, China

Influenza can cause serious illness in older adults, particularly those with diabetes. Although influenza vaccination is an important preventive measure, vaccination uptake among older adults in China remains low. This study aimed to evaluate whether different ways of presenting influenza vaccination information could encourage vaccination among older adults with diabetes in Yangzhou, China. Adults aged 60 to 75 years with diabetes were assigned to one of four study groups: a control group without intervention text messages, a standard information group, a gain-framed information group emphasizing the benefits of vaccination, and a loss-framed information group emphasizing the potential negative consequences of not being vaccinated. The primary outcome was influenza vaccination uptake during follow-up. Secondary outcomes included willingness to receive influenza vaccination and vaccine literacy. The study examined whether information-based interventions could improve vaccination-related outcomes compared with the control group.

A Study to Evaluate the Safety and Efficacy of MK-1406/CD388 for Prevention of Influenza (MK-1406-005/CD388.SQ.3.06)

Approximately one billion cases of seasonal influenza occur annually. Of these, 3 to 5 million illnesses are severe and responsible for up to 650,000 deaths per year (WHO 2025). Yearly administration of an influenza vaccine for the prevention of influenza is currently recommended. However, the real-world vaccine effectiveness varied from 10% to 60% in the general population across the years of 2004 to 2024, with effectiveness in most years below 50% (CDC 2025) and decreasing to as low as 5% in immunocompromised individuals (Hughes 2021). The goal of this study is to learn whether MK-1406 (CD388) can help prevent the flu in people who are at higher risk of becoming seriously ill from influenza. Researchers want to find out if MK-1406 dosed at a single study visit can provide protection against influenza compared with placebo. The study will include adolescents and adults who may be more vulnerable to complications from influenza because of their age, health conditions, or weakened immune systems. Researchers will also evaluate the safety of MK-1406 and how well participants tolerate the study medicine.

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.

COVID-19 Booster and IIV Schedule in Immunocompromised Hosts

The goal of this pragmatic embedded open-label, 2 x 2 factorial phase II randomized controlled trial is to evaluate strategies to improve COVID-19 booster and influenza vaccine immunogenicity in people living with immunocompromising conditions (PLIC). The main questions it aims to answer are: 1. Is co-administration of seasonal inactivated influenza vaccine (IIV) with the most up-to-date recommended COVID-19 booster dose non-inferior in inducing a 1-month peak protective humoral response against COVID-19, compared to a strategy of sequential administration of COVID-19 booster dose followed by seasonal IIV given one month later? 2. Is the administration of the most up-to-date recommended COVID-19 booster doses at 3-month intervals superior at maintaining a longer term protective humoral immune response, compared to booster doses administered at 6-month intervals? Researchers will compare (1) COVID-19 and Influenza vaccines administered at Day 0 + COVID-19 Booster at a 3-month interval, (2) COVID-19 vaccine administered at Day 0 and Influenza vaccine administered at Day 28 + COVID-19 Booster at a 3-month interval, (3) COVID-19 and Influenza vaccines administered at Day 0 + COVID-19 Booster at a 6-month interval, and (4) COVID-19 vaccine administered at Day 0 and Influenza vaccine administered at Day 28 + COVID-19 Booster at a 6-month interval to see if median neutralization capacity of patient sera is non-inferior in the co- vs. sequential administration arms at 1-month after the initial COVID-19 booster and superior in the 3-month interval arms vs. the 6-month interval arms at 12 months after the initial COVID-19 booster. These outcomes will also be compared at 2-months for question 1 and 6-months for question 2. People living with immunocompromising conditions who take part in the trial will have blood samples drawn to verify immune response, be monitored for changes in clinical events and therapies, and complete questionnaires to verify adverse effects, quality of life and economic impact.

Effect of MxA Guidance on Antiviral Treatment in Respiratory Viral Infections

The goal of this clinical trial is to evaluate the effects of myxovirus resistance protein A (MxA)-guided antiviral treatment on treatment duration and adverse outcomes in adults hospitalized with influenza or COVID-19, compared with usual care. Participants will be randomly assigned in a 1:1 ratio to the MxA group or the usual care group. In the MxA group, treating physicians will receive blood MxA test results together with treatment recommendations based on those results. In the usual care group, treating physicians will make antiviral treatment decisions without access to MxA results.

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.

High vs. Standard Dose Influenza Vaccines in Lung Transplant (Repeater)

This will be a follow-up study to the "Comparison of High Dose vs. Standard Dose Influenza Vaccine in Lung Allograft Recipient" study (DMID Protocol Number 22-0014) at Vanderbilt University Medical Center. Lung transplantation is a life-saving therapy for patients with advanced lung disease, and is also associated with an improvement in quality of life. However, due to the need for life-long immunosuppression to prevent acute cellular rejection and chronic lung allograft dysfunction ("chronic rejection"), lung transplant recipients are at risk for developing major infections. In fact, one-year survival is 85%, with infection being the leading cause of death within the first year post-transplant. We will conduct a follow-up phase II, randomized, double-blind trial to assess the impact of subsequent administration of two doses of HD-IIV compared to two doses of SD-IIV among lung recipients during the early post-transplant period. Demonstration of improved immunogenicity from two doses of HD-IIV over consecutive influenza seasons would provide potential broad benefit in reducing influenza disease and its associated complications in lung transplant recipients. Moreover, studying vaccine immunogenicity and safety in the same participants over consecutive years can provide insight into the influence of immunosuppression levels and allograft aging on vaccine-mediated immune modulation. This proposed study design will contribute significantly to influenza vaccination guidance and policy for the highly vulnerable lung transplant population. This proposed study is designed to address several key knowledge gaps in vaccine-mediated protection of lung transplant recipients against influenza: * Is there increased immunogenicity with administration of one or two doses of HD-IIV or SD-IIV in the subsequent season compared to two doses of HD-IIV or SD-IIV in the first season? * What is the durability of the humoral and cellular immune response between influenza seasons and does two doses of HD-IIV or SD-IIV sustain higher HAI titers compared to two doses of HD-IIV or SD-IIV in the first season? * What is the impact of maintenance immunosuppression levels on influenza vaccine immunogenicity within the same participant? * Will the optimal immunogenic vaccination strategy be associated with an acceptable long-term safety profile over successive influenza seasons, including injection-site and systemic reactions, allosensitization, and organ rejection?

Intravenous N-acetylcysteine and Oseltamivir Versus Oseltamivir in Adults Hospitalized With Influenza and Pneumonia

Seasonal influenza epidemics are important causes of morbidity and mortality. Cytokine dysregulation, with high levels of pro-inflammatory cytokines, occurs in patients with severe influenza. Early therapy with a neuraminidase inhibitor (NAI) is associated with better outcome in patients hospitalized with influenza, but significant mortality occurs despite use of antivirals. N-acetylcysteine (NAC) is a modified form of the amino acid cysteine, with anti-oxidant properties. NAC was shown to inhibit the production of pro-inflammatory molecules in lung epithelial cells infected with influenza viruses. Previous case report showed that high dose NAC, administered as continuous intravenous infusion, was effective and safe in improving the clinical outcomes. We aim to perform a randomized controlled trial to evaluate the therapeutic role of adjunctive NAC in the clinical management of patients with influenza complicated by lower respiratory tract involvement and abnormal respiratory status. Such information when available may reveal the potential of NAC for optimization of management of severe influenza, and provide important insights into future adjunctive therapy research.

Immunogenicity of Standard-Dose Versus High-Dose Influenza Vaccines in Older Adults in Singapore

The goal of this clinical trial is to learn if the high-dose influenza vaccine can improve year-round protection in older adults aged 60 years and above. The main question it aims to answer is: • Can the high-dose influenza vaccine induce higher antibody titres at Day 14 post-vaccination compared to standard-dose influenza vaccine? Participants will: * Receive one dose of either the high-dose or standard-dose influenza vaccine * Be followed for one year, with four scheduled visits * Keep a diary of their symptoms for 3 days after vaccination * Report symptoms whenever they experience an acute respiratory infection (ARI), self-perform lateral flow assay (LFA) testing capable of detecting influenza A and B, and send nasal swabs for central testing

Adjunctive Sirolimus and Oseltamivir Versus Oseltamivir Alone for Treatment of Influenza

Seasonal influenza epidemics are important causes of mortality and morbidity. Cytokine dysregulation, with high levels of pro-inflammatory cytokines, occurs in patients with severe influenza A(H1N1)pdm09 virus infection, A(H5N1) infection, and A(H7N9) infection. We aim to investigate the effects of adjunctive sirolimus in adults hospitalized with influenza A or B infections involving the lower respiratory tract.

A Study to Evaluate the Immune Responses of Subunit Influenza Vaccine in Healthy Adults

This is a prospective, open-label, parallel time-cohort study designed to characterize the humoral and cellular immune responses induced by a subunit influenza vaccine (manufactured by Ab\&B Bio-tech Co., Ltd.JS) in healthy adults within one month after vaccination. Eligible participants will receive a single intramuscular dose and will be assigned in parallel to one of two blood-sampling schedules to capture the kinetic profile of the immune response: Group A (pre-vaccination, Day 5, and Day 14 post-vaccination) and Group B (pre-vaccination, Day 7, and Day 21 post-vaccination). Hemagglutination inhibition (HI) antibody titers will be measured to assess humoral immunity, while circulating CD4⁺ and CD8⁺ T-cell levels will be analyzed to evaluate cellular immunity. The occurrence of adverse events（AEs) and serious adverse events(SAEs) within 28 days post-vaccination will be recorded.

Rule-Based High-Risk Flu

Previous work by the study team has shown that informing patients of their high risk of flu and flu-related complications increases their likelihood of getting a flu shot (Rosenbaum et al., 2026). In this work, an artificial intelligence (AI)-based algorithm determined which patients were at high risk for flu. This year, the team will test whether risk messages remain effective when a non-algorithmic rule-based additive risk index (McGovern et al., 2024) is used to identify patients at high risk.

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.

Efficacy, Immunogenicity and Safety of OVX836 Influenza Vaccine 480μg

The present study will evaluate the efficacy, immunogenicity and safety of one dose of OVX836 influenza vaccine 480μg, after intramuscular administration in healthy subjects aged 18-59 years.

A Trial of RLX-2508-102 in Healthy Volunteers

The purpose of this study is to assess safety, PK and immunogenicity profile of a single dose and multiple dose of RLX-2508 in healthy participants across different ethnic backgrounds.