Trial Outcomes & Findings for The Impact of Age on Adaptive Immunity in Adults Infected With Respiratory Syncytial Virus (NCT NCT03728413)

Last Updated: 2026-01-26

Results Overview

To determine the safety and tolerability of experimental challenge with RSV Memphis 37, assessed by the number of participants with challenge-related adverse events. This includes any AEs deemed at least possibly related to the study challenge intervention (RSV Memphis 37). Assessed from the time of inoculation to study completion (Day 180).

Recruitment status

COMPLETED

Study phase

Target enrollment

28 participants

Primary outcome timeframe

180 days

Results posted on

2026-01-26

Participant Flow

Participant milestones

Participant milestones
Measure	Healthy, Non-smoking or Ex-smoking Persons Aged 60 to 75 Years RSV A Memphis 37 will be given as intra-nasal drops to healthy, non-smoking or ex-smoking persons aged 60 to 75 years	Healthy, Non-smoking or Ex-smoking Persons Aged 18 - 40 Years RSV A Memphis 37 will be given as intra-nasal drops to healthy, non-smoking or ex-smoking persons aged 18 - 40 years
Overall Study STARTED	28	0
Overall Study COMPLETED	28	0
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

The Impact of Age on Adaptive Immunity in Adults Infected With Respiratory Syncytial Virus

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Healthy, Non-smoking or Ex-smoking Persons Aged 60 to 75 Years n=28 Participants RSV A Memphis 37 will be given as intra-nasal drops. RSV A Memphis 37: Subjects will be inoculated using intra-nasal drops with diluted inoculum at a given dose divided equally between the two nostrils. Dose: Good Manufacturing Practices-certified RSV Memphis 37 10(4) PFU in 1ml, 25% sucrose/Dulbecco's Modification of Eagle's Medium. Inoculations using intranasal drops will be done using a 1mL pipette with subjects supine. This will be done slowly with sufficient interval between each inoculation (2-3 minutes) to ensure maximum contact time between with the nasal and pharyngeal mucosa. Subjects will be asked not to swallow during the procedure to ensure maximal pharyngeal contact. Following inoculation, advice regarding hand hygiene will be given, subjects will be provided with alcohol hand gel and facemasks to reduce spread of virus in the environment.
Age, Categorical <=18 years	0 Participants n=25 Participants
Age, Categorical Between 18 and 65 years	13 Participants n=25 Participants
Age, Categorical >=65 years	15 Participants n=25 Participants
Age, Continuous	66.46 years STANDARD_DEVIATION 4.16 • n=25 Participants
Sex: Female, Male Female	8 Participants n=25 Participants
Sex: Female, Male Male	20 Participants n=25 Participants
Race/Ethnicity, Customized White British	23 Participants n=25 Participants
Race/Ethnicity, Customized White Irish	1 Participants n=25 Participants
Race/Ethnicity, Customized White Other	2 Participants n=25 Participants
Race/Ethnicity, Customized Black or Black British	1 Participants n=25 Participants
Race/Ethnicity, Customized Asian or Asian British	1 Participants n=25 Participants
Region of Enrollment United Kingdom	28 participants n=25 Participants

PRIMARY outcome

Timeframe: 180 days

Population: In the "Healthy, non-smoking or ex-smoking persons aged 60 to 75 years" arm, 28 participants were enrolled.

Outcome measures

Outcome measures
Measure	Healthy, Non-smoking or Ex-smoking Persons Aged 60 to 75 Years n=28 Participants All enrolled participants are inoculated with RSV Memphis 37. Some meet the criteria for becoming infected, while other participants resist infection i.e. are uninfected.
Number of Participants With Challenge-related Adverse Events Infected	0 Participants
Number of Participants With Challenge-related Adverse Events Uninfected	3 Participants

SECONDARY outcome

Timeframe: Day 0 to Day 14 (14 days)

Population: 1 participant was excluded from analysis as they were co-infected with SARS-CoV-2 and Influenza

This is the total symptom score for the whole 14 day period and is therefore the sum of all the scores from Day 0 to Day 14. Self-reported upper and lower respiratory and systemic symptoms by diary card. A self-completed diary card of upper respiratory tract clinical symptoms was completed on Day 0 and daily for 14 days after inoculation. A total 'upper respiratory clinical symptom score' will be derived using a four-point scale (0-3 for absent, mild, moderate and severe) for each of the following four respiratory symptoms: sneezing, nasal discharge, nasal obstruction, and sore throat, giving a maximum clinical severity score of 12 per day.

Outcome measures

Outcome measures
Measure	Healthy, Non-smoking or Ex-smoking Persons Aged 60 to 75 Years n=27 Participants All enrolled participants are inoculated with RSV Memphis 37. Some meet the criteria for becoming infected, while other participants resist infection i.e. are uninfected.
Symptom Severity in RSV Infection Infected	2.21 Total symptom score Interval 0.95 to 3.74
Symptom Severity in RSV Infection Uninfected	0.75 Total symptom score Interval 0.38 to 0.88

SECONDARY outcome

Timeframe: Day 0 to Day 28 (28 days)

Population: 1 participant was excluded from analysis as they were co-infected with SARS-CoV-2 and Influenza

Change from baseline in viral load by qPCR of 28 days post inoculation.

Outcome measures

Outcome measures
Measure	Healthy, Non-smoking or Ex-smoking Persons Aged 60 to 75 Years n=27 Participants All enrolled participants are inoculated with RSV Memphis 37. Some meet the criteria for becoming infected, while other participants resist infection i.e. are uninfected.
Nasal Viral Load Measurement in RSV Infection Infected	28.88 Nasal Viral Load (log10 copies per mL) Interval 15.62 to 44.2
Nasal Viral Load Measurement in RSV Infection Uninfected	0.00 Nasal Viral Load (log10 copies per mL) Interval 0.0 to 0.0

OTHER_PRE_SPECIFIED outcome

Timeframe: Day 0 to Day 28 (28 days)

Population: 1 participant was excluded from analysis as they were co-infected with SARS-CoV-2 and Influenza

Mean titre of RSV specific antibodies from the Day 0, Day 7, Day 10, Day 14 and Day 28 sampling timepoints post inoculation in the infected vs uninfected group.

Outcome measures

Outcome measures
Measure	Healthy, Non-smoking or Ex-smoking Persons Aged 60 to 75 Years n=27 Participants All enrolled participants are inoculated with RSV Memphis 37. Some meet the criteria for becoming infected, while other participants resist infection i.e. are uninfected.
Antibody Responses to RSV Infection Infected	12.27 Anti-F protein Serum IgG titer Interval 11.29 to 13.33
Antibody Responses to RSV Infection Uninfected	9.55 Anti-F protein Serum IgG titer Interval 7.065 to 12.9

OTHER_PRE_SPECIFIED outcome

Timeframe: Day 0 to Day 28 (at 0,7,10,14 and 28 days post inoculation)

Population: No measurements were performed for this outcome measure.

Frequency of RSV specific T cells measured at 0,7,10,14 and 28 days post inoculation

Outcome measures

Outcome data not reported

Adverse Events

Healthy, Non-smoking or Ex-smoking Persons Aged 60 to 75 Years

Serious events: 0 serious events

Other events: 23 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Healthy, Non-smoking or Ex-smoking Persons Aged 60 to 75 Years n=28 participants at risk RSV A Memphis 37 will be given as intra-nasal drops. RSV A Memphis 37: Subjects will be inoculated using intra-nasal drops with diluted inoculum at a given dose divided equally between the two nostrils. Dose: Good Manufacturing Practices-certified RSV Memphis 37 10(4) PFU in 1ml, 25% sucrose/Dulbecco's Modification of Eagle's Medium. Inoculations using intranasal drops will be done using a 1mL pipette with subjects supine. This will be done slowly with sufficient interval between each inoculation (2-3 minutes) to ensure maximum contact time between with the nasal and pharyngeal mucosa. Subjects will be asked not to swallow during the procedure to ensure maximal pharyngeal contact. Following inoculation, advice regarding hand hygiene will be given, subjects will be provided with alcohol hand gel and facemasks to reduce spread of virus in the environment.
Cardiac disorders Hypotension	14.3% 4/28 • Number of events 7 • 180 days
Infections and infestations Bleeding	25.0% 7/28 • Number of events 9 • 180 days
Infections and infestations COVID-19	7.1% 2/28 • Number of events 2 • 180 days
Infections and infestations Chills	7.1% 2/28 • Number of events 2 • 180 days
Infections and infestations Influenza-like-illness	7.1% 2/28 • Number of events 2 • 180 days
Respiratory, thoracic and mediastinal disorders Hypoxemia	14.3% 4/28 • Number of events 5 • 180 days
Respiratory, thoracic and mediastinal disorders Airway inflammation	7.1% 2/28 • Number of events 2 • 180 days
Respiratory, thoracic and mediastinal disorders Cough	14.3% 4/28 • Number of events 4 • 180 days
Gastrointestinal disorders Nausea	7.1% 2/28 • Number of events 3 • 180 days
Nervous system disorders Pre-syncopal epiosode	7.1% 2/28 • Number of events 2 • 180 days
Respiratory, thoracic and mediastinal disorders Sore throat	7.1% 2/28 • Number of events 2 • 180 days

Additional Information

Professor Christopher Chiu

Imperial College London

Phone: 02083832301

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place