Scientists deliberately infect older adults with RSV to unlock immune secrets

NCT ID NCT07713628

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Recruiting now
This trial is taking on new participants right now.
Not yet recruiting This study
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
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Paused for now. It may or may not start again.
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Running, but no longer taking on new participants.
Completed
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
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Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
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Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
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Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

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Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jul 20, 2026 · Last updated Jul 21, 2026 · Updated 1 time

Summary

This study gives healthy volunteers aged 65 to 75 a carefully measured dose of RSV B virus to see how their immune system responds. Participants stay in a quarantine unit for 10 days for close monitoring and daily samples. The goal is to understand how RSV infection progresses in older adults and to gather data that could improve future vaccines and treatments.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
RSV B challenge virus
What this could lead to
If successful, this study could help develop better vaccines or treatments for RSV in older adults, who are at higher risk for severe illness.
What could go wrong
This is a small, early-stage human challenge study with only 20 participants, so results may not apply to the broader population. There is a risk of mild to moderate RSV symptoms.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Not a phased trial

Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.

Participants

About 20 people

The number the study aims to enrol. It can still change while the study runs.

Expected to start

Aug 2026

An estimate. Start dates often move.

Expected to finish

May 2028

An estimate. End dates often move.

Lead sponsor

Other sponsor

The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

65 to 75 years

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Aged between 65 to 75years (inclusive) at Day 0. 2. Willing and able to commit to participation in the study. 3. Adequate understanding of the study, the procedures involved, and able to provide written informed consent prior to any study procedures. 4. In good health with no history of clinically significant medical conditions (as described in exclusion criteria) that would interfere with participant safety. A forced expiratory volume in 1 second (FEV1) and a forced vital capacity (FVC) \<80% of predicted value calculated using ATS/ERS guidance. Exclusion Criteria: 1. Any significant medical condition or prescribed drug deemed by the Investigator to deem the participant unsuitable for the study. 2. History or evidence of any clinically significant or currently active: 1. Cardiovascular, thromboembolic or cerebrovascular disease. 2. Chronic respiratory disease (e.g. asthma, COPD, rhinitis, sinusitis, reactive airway disease, pulmonary hypertension or a chronic lung condition) in adulthood (a history of childhood asthma without respiratory disease in adulthood may be accepted at the PIs discretion). 3. Significant or severe wheeze, or respiratory symptoms (including wheeze) which has ever resulted in hospitalisation. 4. Known bronchial hyperactivity to viruses. 5. Diabetes mellitus. 6. Migraine with associated neurological symptoms such as hemiplegia or vision loss. Cluster headache/migraine or prophylactic treatment for migraine. 7. History or evidence of autoimmune disease or known/suspected immunodeficiency of any cause, including asplenia or history of recurrent severe infections. 8. Immunosuppression of any type. 9. Known IgA deficiency, immotile cilia syndrome, or Kartagener's syndrome. 10. Known coagulation disorder or anticoagulant therapy. 11. Psychiatric illness including participants with a history of depression and/or anxiety with associated severe psychiatric comorbidities, for example psychosis. Consider exclusion in the following cases: Participants with history of anxiety-related symptoms of any severity within the last 2 years if the Generalized Anxiety Disorder-7 score is ≥4; Participants with a history of depression of any severity within the last 2 years if the Patient Health Questionnaire-9 score is ≥4; . Severe claustrophobia 12. Other major disease that, in the opinion of the Investigator, could interfere with a participant completing the study and necessary investigations. 13. Concurrent serious illness including history of malignancy that could interfere with the aims of the study or a participant completing the study. Permissible stable conditions that are well controlled might not be exclusionary and will be assessed by the PI on a case-by-case basis. These include, but will not be limited to: well controlled Hypertension, Sensitive Bladder, Hiatus Hernia, Vitamin D Deficiency, Diverticulitis, Renal Calculi, Depression (well managed), Perioral Dermatitis, Hypercholesterolemia (diet or well medically controlled), Macular Degeneration, Mild Arthritis. 3. Any significant abnormality altering the anatomy or function of the nose or nasopharynx in a substantial way, including nasopharyngeal malignancy, arterio-venous malformation, or undiagnosed nasopharyngeal mass. 4. A history of clinically significant epistaxis (large nosebleeds) within 3 months of Day 0. 5. Nasal or sinus surgery within 3 months of Day 0. 6. Any anatomic or neurologic abnormality impairing the gag reflex or associated with increased risk of aspiration. 7. Receipt of systemic glucocorticoids (in a dose ≥ 5 mg prednisone daily or equivalent) within one month, or any other cytotoxic or immunosuppressive drug within 6 months prior to Day 0. 8. A history of inhaled bronchodilator or inhaled steroid use within the prior 12 months to Day -14. 9. Receipt of any vaccine within 30 days of Day -14 or planned during the study period, until the last follow-up visit (Day 90). 10. Participation in an investigational drug or device study within 3 months prior to Day 0. 11. Receipt of blood or blood products, or loss (including blood donations) of 550 mL or more of blood during the 6 months prior to Day -14. 12. History of difficult blood draw, syncope or poor tolerance of sampling procedures as assessed by clinical study team. 13. History of anaphylaxis and/or a history of severe allergic reaction or significant intolerance to any food or drug, as assessed by the PI. 14. Allergic symptoms present at baseline (at screening, day -14 or day 0). 15. Clinically active rhinitis (including hay fever) or history of moderate to severe rhinitis, or history of seasonal allergic rhinitis likely to be active at the time of inclusion into the study and/or requiring regular nasal corticosteroids on an at least weekly basis, within 30 days of enrolment. 16. Habitual use of any medication or other product (prescription or over the counter) for symptoms of rhinitis or nasal congestion the 3 months prior to Day -14. 17. Receipt of RSV vaccine at any time or planned RSV vaccination in the 3 months following inoculation. 18. Virologically confirmed RSV infection within 6 months of Day 0. 19. Prior inoculation with a virus from the same virus family (Pneumoviridiae) as the challenge virus. 20. Prior participation in another controlled human infection study with a respiratory virus in the preceding 6 months taken from the date of viral challenge in the previous study to the date of expected viral challenge in this study. 21. Acute upper respiratory infection (URI or sinusitis) in the 6 weeks prior to Day-14 baseline visit. 22. Presence of cold-like symptoms and/or fever (defined as participant presenting with a temperature reading of \>37.9ºC) on Day -14, Day -1 or Day 0. 23. A respiratory PCR test that is indicative of Influenza, RSV or other respiratory virus infection, including asymptomatic infections, determined by a test on admission to quarantine (Day -1). 24. Clinically relevant abnormality on chest X-ray. 25. A total body weight of ≤ 50kg and a Body Mass Index (BMI) ≤18 kg/m2 or ≥28 kg/m2. • The upper limit of BMI may be increased to ≤ 30kg/m2 at the PI's discretion, in the case of physically fit muscular individual or other variation of normal). 26. Any abnormal finding on screening safety blood tests deemed to be clinically significant by the Investigator including positive HIV, active/chronic hepatitis B or C test. 27. Any ECG abnormality deemed to be clinically significant by the Investigator. 28. Significant history or presence of drug or alcohol misuse. 1. Participants will be required to have a negative urine drug test at screening. If positive, this will be exclusionary. 2. Current use of more than 21 units alcohol per week, drug abuse, or regular use of sedatives, hypnotics, tranquilisers or any other addictive agent are exclusionary. 29. Current use of any recreational drugs, including injected, taken through the nose or inhaled route. 30. Regular smoking and/or vaping and/or using other nicotine-containing products in the past 3 months OR: 1. \>5 pack-year lifetime history by self-report (5 pack years is equivalent to one pack of 20 cigarettes per day for 5 years). 2. Participants will be required to have a negative urine cotinine test at screening. If positive, this will be exclusionary. 31. Those in close domestic contact (i.e. sharing a household with, caring for, or daily face to face contact) with children under 4 years, clinically vulnerable and/or immunosuppressed persons, or those with chronic respiratory disease for 30 days after RSV B inoculation.

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