Streptococcus PneumoniaChallenge3NCT05535868

Experimental Human Pneumococcal Challenge With SPN3

A study testing Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3) and Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V) in people with Streptococcus Pneumonia and Controlled Human Infection, run by Liverpool School of Tropical Medicine at 1 site in United Kingdom.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

The 'Experimental Human Pneumococcal challenge' (EHPC) model is a way of putting drops of bacteria into the nose. Investigators have studied this model of putting bacteria in the nose safely in over 1500 volunteers over the past decade with no serious side effects and now want to test the model using a different… Read more about this study

Who is it for?: Ages 18 to 50 yearsHealthy volunteers can take part
Conditions the study is for: Streptococcus Pneumonia, Controlled Human Infection
What is being tested?: Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3) and Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 91 participants
Where: 1 siteUnited Kingdom
Study dates: 1 Aug 2022to 21 Nov 2023
Phase: Interventional
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 50 years
All sexes
Healthy volunteers accepted
Adult

Who may be able to join

None listed.

Who cannot join

o Currently involved in another study unless observational or non-interventional, excluding the EHPC bronchoscopy study (at the discretion of the study team). This is to ensure no harm comes to the participants through over-sampling.
Participant in any previous EHPC trial in past year
Participant in previous EHPC trial inoculated with SPN3 in the last 3 years
Participant in EHPC Pneumo 2 trial
Vaccination: Previous pneumococcal vaccination PPV23 or PCV13 (routine in babies born in the UK since 2005) or PCV10. This can be self-reported or confirmed from GP questionnaire (GPQ) if deemed necessary at clinician discretion.
Allergy: to penicillin/amoxicillin

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Health history (self-reported or confirmed by GPQ or medical summary if felt to be necessary at clinician discretion):
Chronic ill health including immunosuppressive history, diabetes, asthma (on regular medication), recurrent otitis media or other respiratory disease.
Medication that may affect the immune system e.g., steroids, inflammation altering or disease-modifying anti-rheumatoid drugs.
Long term use of antibiotics for chronic infection.
Major pneumococcal illness requiring hospitalisation in the last 10 years.
Other conditions considered by the clinical team as a concern for participant safety or integrity of the study
Significant mental health problems (uncontrolled condition or requiring previous admission to a psychiatric unit) that would impair ability to participate
Direct caring role or close contact with individuals at higher risk of infection during the inoculation period if personal protective equipment (PPE) not worn:
Children under 5 years age
Adults with chronic ill health or immunosuppression
Hospital patients
Smoker:
Current or ex-smoker (daily cigarettes, daily e-cigarettes/vaping and daily smoking of recreational drugs) in the last 6 months. Participants who smoke <5 cigarettes per week may be included.
Previous significant smoking history (>20 cigarettes per day for 20 years or equivalent [>20 pack years]).
Biologically female participants of child-bearing potential (WOCBP) who are:
Currently pregnant/lactating
Intending on becoming pregnant during the study
Not deemed to have effective birth control
History of or current drug or alcohol abuse:
Men should not drink >3 units/day regularly
Women should not drink >2 units/day regularly
Overseas travel planned in follow up period of study visits
Natural SPN 3 colonisation in baseline nasal wash - if a participant is colonised with non-SPN3 pneumococcus, they can be included as part of exploratory analyses, but would not be included in the primary analysis
STOP criteria - participants who meet STOP criteria at time of screening (Table 3) 6.3 Temporary Exclusion Criteria
Ongoing COVID-19 symptoms (fever, cough, shortness of breath, anosmia or ageusia) or confirmed current COVID-19 infection. Participants with resolved COVID-19 after their UKHSA determined isolation period has ended can be included.
Current/acute illness within 14 days prior to inoculation if COVID-19 negative
Positive COVID-19 swab whether symptomatic or asymptomatic within 10 days of inoculation
Currently isolating following exposure to COVID-19 as per UKHSA guidance
Antibiotic use within 28 days of inoculation.
Participants who have been temporarily excluded at screening may be re-screened at a later date to assess their eligibility at this time for inclusion into the study. At this point, the participant would be re-consented if their initial written consent was given >4 months prior to this date.
Vaccination 21 days prior to inoculation

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site

Liverpool School of Tropical Medicine
Liverpool, L7 8XZ

Other trials in United Kingdom

About this study

Official title: Serotype 3 Experimental Human Pneumococcal Challenge; Dose Ranging and Reproducibility in a Healthy Volunteer Population

The aim of this study is to determine how much pneumococcus is needed to achieve nasal colonisation and how long the bacteria live in the nose for before natural immune responses eradicate them. By doing this, Investigators will then be able to test how well future vaccines prevent colonisation with pneumococcus. Investigators want to learn more about how the immune system responds to nasal colonisation with pneumococcus, again to help with development of new vaccines.

Read the detailed description

In this study, investigators propose to determine the optimal dose and isolate of SPN3 to establish colonisation in the human nasopharynx, as well as improving knowledge of immune responses to SPN3 colonisation. The results from this study will be used to inform development of improved SPN3 vaccines and to inform design of future pneumococcal vaccine RCTs.

To increase the relevance of the EHPC model and its use for assessing future vaccines such as V114, investigators are proposing here to set up an EHPC model with carefully selected non-proprietary SPN3 strains. Investigators will conduct a safety and dose-ranging study to determine the optimum SPN3 strain and dose for colonisation acquisition and confirm the dose in a subsequent larger cohort in a reproducibility study and will study mucosal and systemic immune responses to this serotype and their association with protection against colonisation acquisition and clearance.

Conditions: Streptococcus Pneumonia, Controlled Human Infection
Being tested: Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3), Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)
Keywords: streptococcus pneumoniae, pneumococcus, controlled human infection, serotype 3, SPN3, Adult, Healthy volunteers
Medical subject headings: Pneumonia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3)Other
Also called EHPC, SPN3 inoculation, LIV014-S3, Targeted booster
Dose-ranging and reproducibility study of SPN3 inoculation AND targeted booster inoculation at day-14, where prime inoculation fails to lead to experimental colonisation
Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)Other
Also called EHPC, SPN3 inoculation, MLW-10V, Targeted booster
Dose-ranging study of SPN3 inoculation AND targeted booster inoculation at day-14, where prime inoculation fails to lead to experimental colonisation

Study groups in NCT05535868
Study group	Role	What they receive
MLW-10V, 10000 CFU/ml	Experimental	Malawi isolate, low dose Receives: Other: Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)
MLW-10V, 20000 CFU/ml	Experimental	Malawi isolate, intermediate dose Receives: Other: Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)
MLW-10V, 80000 CFU/ml	Experimental	Malawi isolate, higher dose Receives: Other: Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)
LIV014-S3, 10000 CFU/ml	Experimental	Liverpool isolate, low dose Receives: Other: Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3)
LIV014-S3, 20000 CFU/ml	Experimental	Liverpool isolate, intermediate dose Receives: Other: Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3)
LIV014-S3, 80000 CFU/ml	Experimental	Liverpool isolate, higher dose (includes dose-ranging and reproducibility study participants, since the reproducibility study only included this isolate and dose) Receives: Other: Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3)

What is being measured

The primary outcome is the main question the study is designed to answer.

To Determine the Optimal SPN3 Dose and Isolate to Establish Colonisation of the Nasopharynx in Healthy Adults
The proportion of participants with experimental SPN3 colonisation of the nasopharynx, determined by SPN3 presence in classical microbiological culture in at least one nasal wash (NW) sample, at any time point following one or two inoculations (combined and individually). This will be assessed for each isolate and dose separately.
Measured: From inoculation (day 0) to the final visit for each participant (28 days post-inoculation)

Secondary outcomes (2)

To Determine the Density of Experimental SPN3 Colonisation of the Nasopharynx.
The bacterial density of experimental SPN3 colonisation of the nasopharynx in NW, at each and any time point following one or two inoculations (combined and individually), determined by classical microbiological culture, assessed for each isolate and dose separately. The number of participants analysed includes only the participants who developed SPN3 colonisation in each arm/group, rather than the total number of participants inoculated.
Measured: From inoculation (day 0) to the final visit for each participant (28 days post-inoculation)
To Determine the Duration of Experimental SPN3 Colonisation of the Nasopharynx.
The duration of experimental SPN3 colonisation of nasopharynx determined by the last NW sample following one or two inoculations in which SPN3 is detected by classical microbiological culture, assessed for each isolate and dose separately. Note - number of participants analyzed in this outcome measure is different (and lower) than overall number of participants in participant flow section, because duration of colonisation can only apply to participants who developed experimental colonisation from at least one timepoint post-inoculation.
Measured: From inoculation (day 0) to the final visit for each participant (28 days post-inoculation)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

1 Aug 202221 Nov 2023

First posted10 Sep 2022
Study start1 Aug 2022
Primary completion21 Nov 2023
Study completion21 Nov 2023

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for Streptococcus PneumoniaStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase N/A
Primary purpose: Prevention
Allocation: Non-randomised
Intervention model: Sequential
Masking: None (open label)
Enrolment: 91 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05535868
Sponsor's protocol ID: 22-003
Acronym: Challenge3
Status last verified: Jun 2026
First submitted: 14 Apr 2022
Last updated: 29 Jun 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Publications

Hazenberg P, Robinson RE, Farrar M, Solorzano C, Hyder-Wright A, Liatsikos K, Brunning J, Fleet H, Bettam A, Howard A, Kenny-Nyazika T, Urban B, Mitsi E, El Safadi D, Davies K, Lesosky M, Gordon SB, Ferreira DM, Collins AM. Serotype 3 Experimental Human Pneumococcal Challenge (EHPC) study protocol: dose ranging and reproducibility in a healthy volunteer population (challenge 3). BMJ Open. 2024 Jan 10;14(1):e075948. doi: 10.1136/bmjopen-2023-075948.
PubMed 38199622

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Streptococcus Pneumonia trials

Study at a glance

From the registry record, last updated by the sponsor on 29 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Serotype 3 Experimental Human Pneumococcal Challenge; Dose Ranging and Reproducibility in a Healthy Volunteer Population
ClinicalTrials.gov ID: NCT05535868
Acronym / sponsor ID: Challenge3 / 22-003
Conditions: Streptococcus Pneumonia, Controlled Human Infection
Keywords: streptococcus pneumoniae, pneumococcus, controlled human infection, serotype 3, SPN3, Adult, Healthy volunteers
Study type: Interventional
Recruitment status: Completed
Enrolment: 91 participants (actual)
Lead sponsor: Liverpool School of Tropical MedicineUniversity, hospital or other
Collaborators: Merck Sharp & Dohme LLC, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Liverpool University Hospitals NHS Foundation Trust, University of Oxford
Study start: 1 Aug 2022 (actual)
Primary completion: 21 Nov 2023 (actual)
Study completion: 21 Nov 2023 (actual)
First posted: 10 Sep 2022 (actual)
Results: Posted 29 Jun 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Prevention
Allocation: Non-randomised
Intervention model: Sequential
Masking: None (open label)
Number of arms: 6

Arm	Type	Receives
MLW-10V, 10000 CFU/ml	Experimental	Other: Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)Malawi isolate, low dose
MLW-10V, 20000 CFU/ml	Experimental	Other: Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)Malawi isolate, intermediate dose
MLW-10V, 80000 CFU/ml	Experimental	Other: Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)Malawi isolate, higher dose
LIV014-S3, 10000 CFU/ml	Experimental	Other: Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3)Liverpool isolate, low dose
LIV014-S3, 20000 CFU/ml	Experimental	Other: Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3)Liverpool isolate, intermediate dose
LIV014-S3, 80000 CFU/ml	Experimental	Other: Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3)Liverpool isolate, higher dose (includes dose-ranging and reproducibility study participants, since the reproducibility study only included this isolate and dose)

Who may qualify

Ages: 18 to 50 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult

Key inclusion criteria (0 listed)

Key exclusion criteria (37 listed)

o Currently involved in another study unless observational or non-interventional, excluding the EHPC bronchoscopy study (at the discretion of the study team). This is to ensure no harm comes to the participants through over-sampling.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Serotype 3 Experimental Human Pneumococcal Challenge - Liverpool Isolate (LIV014-S3)Also: EHPC, SPN3 inoculation, LIV014-S3, Targeted boosterDose-ranging and reproducibility study of SPN3 inoculation AND targeted booster inoculation at day-14, where prime inoculation fails to lead to experimental colonisation	Other	LIV014-S3, 10000 CFU/ml, LIV014-S3, 20000 CFU/ml, LIV014-S3, 80000 CFU/ml
Serotype 3 Experimental Human Pneumococcal Challenge - Malawi Isolate (MLW-10V)Also: EHPC, SPN3 inoculation, MLW-10V, Targeted boosterDose-ranging study of SPN3 inoculation AND targeted booster inoculation at day-14, where prime inoculation fails to lead to experimental colonisation	Other	MLW-10V, 10000 CFU/ml, MLW-10V, 20000 CFU/ml, MLW-10V, 80000 CFU/ml

Primary outcome

To Determine the Optimal SPN3 Dose and Isolate to Establish Colonisation of the Nasopharynx in Healthy Adults
Time frame: From inoculation (day 0) to the final visit for each participant (28 days post-inoculation)
The proportion of participants with experimental SPN3 colonisation of the nasopharynx, determined by SPN3 presence in classical microbiological culture in at least one nasal wash (NW) sample, at any time point following one or two inoculations (combined and individually). This will be assessed for each isolate and dose separately.

2 secondary outcomes

To Determine the Density of Experimental SPN3 Colonisation of the Nasopharynx.
Time frame: From inoculation (day 0) to the final visit for each participant (28 days post-inoculation)
To Determine the Duration of Experimental SPN3 Colonisation of the Nasopharynx.
Time frame: From inoculation (day 0) to the final visit for each participant (28 days post-inoculation)

Results and safety

Results posted to the registry on 29 Jun 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
MLW-10V, 10000 CFU/ml	9	9
MLW-10V, 20000 CFU/ml	10	10
MLW-10V, 80000 CFU/ml	10	10
LIV014-S3, 10000 CFU/ml	7	7
LIV014-S3, 20000 CFU/ml	10	10
LIV014-S3, 80000 CFU/ml	40	40

Primary outcome: To Determine the Optimal SPN3 Dose and Isolate to Establish Colonisation of the Nasopharynx in Healthy Adults

Time frame: From inoculation (day 0) to the final visit for each participant (28 days post-inoculation). Count of participants. Unit: Participants

Measure	MLW-10V, 10000 CFU/ml n = 9	MLW-10V, 20000 CFU/ml n = 10	MLW-10V, 80000 CFU/ml n = 10	LIV014-S3, 10000 CFU/ml n = 7	LIV014-S3, 20000 CFU/ml n = 10	LIV014-S3, 80000 CFU/ml n = 40
Rate of experimental colonisation after prime inoculation: Experimental colonisation following targeted booster inoculation	4	1	6	1	4	28
Rate of experimental colonisation after prime inoculation: Negative for experimental colonisation after targeted booster inoculation	5	9	4	6	6	12
Rate of experimental colonisation after targeted booster: Experimental colonisation following targeted booster inoculation	5	2	8	1	8	34
Rate of experimental colonisation after targeted booster: Negative for experimental colonisation after targeted booster inoculation	4	8	2	6	2	6

Population analysed: Table shows cumulative proportion of participants with experimental colonisation following prime inoculation by day 13 post-inoculation (1st row) and following targeted booster inoculation by day 28 post-prime inoculation (second row)

2 secondary outcomes are reported in the full results.

Adverse events

Time frame: For all adverse events, these are from enrolment until end of follow-up, up to 28 days post-inoculation.. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
MLW-10V, 10000 CFU/ml	0 of 9 (0%)	1 of 9 (11.1%)	0 of 9
MLW-10V, 20000 CFU/ml	0 of 10 (0%)	9 of 10 (90%)	0 of 10
MLW-10V, 80000 CFU/ml	0 of 10 (0%)	5 of 10 (50%)	0 of 10
LIV014-S3, 10000 CFU/ml	0 of 7 (0%)	5 of 7 (71.4%)	0 of 7
LIV014-S3, 20000 CFU/ml	0 of 10 (0%)	5 of 10 (50%)	0 of 10
LIV014-S3, 80000 CFU/ml	0 of 40 (0%)	28 of 40 (70%)	0 of 40

Limitations and caveats (from the sponsor): This study was conducted in a healthy UK volunteer populatio (so potentially less translatable to those with chronic illnesses or of different ages or from different countries), used one serotype and two isolates only. Data collected for a few e-diary symptoms carried a high degree of subjectivity, such as trouble concentrating; these will be reconsidered in future studies.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 29 Jun 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Background: PubMed 38199622Hazenberg P, Robinson RE, Farrar M, Solorzano C, Hyder-Wright A, Liatsikos K, Brunning J, Fleet H, Bettam A, Howard A, Kenny-Nyazika T, Urban B, Mitsi E, El Safadi D, Davies K, Lesosky M, Gordon SB, Ferreira DM, Collins AM. Serotype 3 Experimental Human Pneumococcal Challenge (EHPC) study protocol: dose ranging and reproducibility in a healthy volunteer population (challenge 3). BMJ Open. 2024 Jan 10;14(1):e075948. doi: 10.1136/bmjopen-2023-075948.
Individual participant dataSharing planned: No

Related trials for Streptococcus Pneumonia

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Andrea Collins, MBChB, PhD principal investigator

Senior Clinical Lecturer

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 0 inclusion and 37 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 29 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 29 Jun 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

To Determine the Optimal SPN3 Dose and Isolate to Establish Colonisation of the Nasopharynx in Healthy Adults (time frame: From inoculation (day 0) to the final visit for each participant (28 days post-inoculation)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05535868, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Jun 2026.