Pneumococcal DiseasePhase 4RATIONALE-15NCT06731374
Carriage to Assess Protection of New Pneumococcal Vaccines - PCV15
A Phase 4 study testing PCV15 and Streptococcus pneumoniae serotype 3 in people with Pneumococcal Disease and Pneumococcal Carriage, run by University of Oxford at 2 sites in United Kingdom.
Trial summary
Streptococcus pneumoniae (pneumococcus) is a bacterium that causes just under four million serious infections every year. It is normal for pneumococcus bacteria to live in the noses of healthy adults and children as part of the nasal microflora without causing harm. This is called "carriage". Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Pneumococcal Disease, Pneumococcal Carriage
- What is being tested?
- PCV15 and Streptococcus pneumoniae serotype 3
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 106 participants
- Where
- 2 sitesUnited Kingdom
- Study dates
- 24 Feb 2025to Dec 2026
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
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
- Adults between 18 to 50 years old (inclusive) at the time of enrolment.
- Medically healthy, such that according to investigator judgement, hospitalisation within the study period is not anticipated, and the participant appears likely to be able to remain a study participant through to the end of protocol-specified follow-up. Planned elective procedures for pre-existing conditions may be allowable.
- Fluent spoken English - to ensure a comprehensive understanding of the research project and their proposed involvement.
- Able to attend the scheduled visits and to comply with all study procedures, including internet access for the recording of electronic diary after inoculation.
- Willing and able to give informed consent for participation in the study.
- Willing to allow confirmation of past medical history either through provision of, or access to, a medical record summary or other medical documentation or allowing investigators to obtain a copy of their medical history from their GP practice or accessed via electronic patient records.
Show all 9Show fewer
- Willing to allow their GP and/or consultant, if appropriate, to be notified of participation in the study.
- Willing to provide their national insurance number or passport number to be registered on The Over-Volunteering Prevention System (TOPS).
- For participants of childbearing potential only: willing to use effective contraception for the duration of the study AND to have a pregnancy test on the day of screening and challenge.
Who cannot join
- Research Participants:
- Participation in another research study, in which procedures performed could compromise the integrity of this study (such as significant volumes of blood taken), or are planning to do so within the trial period
- Currently a participant in a previous EHPC trial within the last 2 years or at the discretion of the study team
- Vaccination (self-reported or confirmed from GP questionnaire or medical records/summary if deemed necessary at clinician discretion):
- Have had any previous pneumococcal vaccination in the past 5 years (including in a research study)
- Planned vaccination during the study
Show all 49Show fewer
- Allergy:
- Have an allergy to penicillin or amoxicillin (for main study cohort only)
- History of a bleeding disorder (e.g., Factor deficiency, coagulopathy, or platelet disorder), or prior history of significant bleeding or bruising following IM injections or venepuncture
- Have previous anaphylaxis or severe adverse reaction to any component/excipient of the vaccine or to any vaccine
- Allergy to Lidocaine local anaesthetic (for nasal biopsy cohort only)
- Health History (self-reported or confirmed from GP questionnaire or medical records/summary if deemed necessary): moderate ill health including but not limited to:
- Asplenia or dysfuction of the spleen
- Chronic respiratory disease (e.g. asthma [on medication], COPD, emphysema, bronchiectasis)
- Chronic heart disease (e.g. angina, ischaemic heart disease, chronic heart failure) [controlled stable hypertension +/- angina may be included].
- Chronic kidney disease (e.g. nephrotic syndrome, kidney transplant, on dialysis)
- Chronic liver disease (e.g. cirrhosis, biliary atresia, hepatitis)
- Chronic neurological conditions
- Connective tissue disease
- Dementia
- Diabetes mellitus (including diet controlled)
- Immunosuppression or history of receiving immunosuppressive therapy - at the discretion of the investigator
- Individuals with cochlear implants
- Individuals with major cerebrospinal fluid leaks (e.g. following trauma, major skull surgery, or requiring CSF shunt)
- Recurrent otitis media.
- History of significant unexplained bleeding after a surgical or dental procedure (for nasal biopsy participants only)
- Have any uncontrolled medical/surgical/mental health conditions at the discretion of the study doctor.
- Major pneumococcal illness requiring hospitalisation within the last 10 years.
- Significant mental health condition (e.g previous admissions in a psychiatric unit, at the discretion of the clinician) that would impair the participant's ability to participate in the study
- Taking Medications:
- Any medication that may affect the immune system in the last 3 months (e.g. systemic steroids [IM/IV], Roaccutane, disease modifying anti-rheumatoid drugs)
- Long-term use of antibiotics (see also section of Temporary Exclusion Criteria)
- Use of any medication or other product (prescription or over-the-counter) for symptoms of rhinitis or nasal congestion within the last 1 month
- Use of any medication affecting blood clotting (any oral/injectable anticoagulants)
- Female participants who are pregnant, lactating or intending on becoming pregnant during the study
- Direct caring role or close contact with individuals at higher risk of infection (for main study cohort only):
- Children under 5 years of age
- Chronic ill health or immunosuppressed adults
- Older adults
- Smoker:
- Current or ex-smoker (regular cigarettes/cigars/e-cigarette/vaping/smoking of recreational drugs) in the last 6 months
- Previous significant smoking history (more than 20 cigarettes per day for 20 years or the equivalent [>20 pack years])
- Suspected or known current alcohol or drug abuse, as per investigators discretion
- Overseas travel during the follow-up period (from the time point of inoculation to antibiotic treatment or completion of the 28 day follow up period post inoculation)
- Any other issue which, in the opinion of the study staff, may:
- Put the participant or their contacts at risk because of participation in the study
- Adversely affect the interpretation of the study results, or
- Impair the participant's ability to participate in the study
- Study site staff or a partner or dependent child of study site staff
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom2 sites, 2 recruiting
- Recruiting
Liverpool Vaccine Group
Liverpool, North West, L7 8XZ
Angela Hyder-Wright, +44 7740 410 290, Angela.Hyder-Wright@lstmed.ac.uk
Liverpool Vaccine Group - LSTM, +44 7740 410 290, LVGClinical@lstmed.ac.uk
- Recruiting
Oxford Vaccine Group
Oxford, Oxfordshire, OX3 7LE
Carla Solorzano-Gonzalez, PhD, + 44 1865611400, Carla.SolorzanoGonzalez@paediatrics.ox.ac.uk
Oxford Vaccine Group, + 44 1865611400, info@ovg.ox.ac.uk
About this study
Official title: A Phase IV, Experimental Human Pneumococcal Challenge (EHPC) Model to Investigate Streptococcus Pneumoniae Serotype 3 (SPN3) Colonisation Following PCV15, a Double Blind Randomised Controlled Trial (DBRCT) in Healthy Participants Aged 18 - 50 Years in the UK.
Streptococcus pneumoniae (pneumococcus) is a bacterium that causes just under four million serious infections every year. It is normal for pneumococcus bacteria to live in the noses of healthy adults and children as part of the nasal microflora without causing harm. This is called "carriage". But the bacteria can still be passed on to other people. If they are at-risk, for example elderly, or very young, or have pre-existing health conditions, the pneumococcus bacteria can cause pneumonia, which can cause serious life-threatening illness.
Pneumococcus bacteria are surrounded by a sugar capsule. But the capsule does not always have the same components. As a result, the bacteria are classified into more than 100 different types. To make them effective, the vaccines that are currently available contain the sugar capsules of the most common pneumococcal types that cause disease.
Read more
One such vaccine - PCV13 - has been effective globally in protecting against pneumococcus disease. It works because it controls the "carriage" (how a person carries the bacteria in their nose) of 13 types of the bacteria. Vaccines giving protection against other types of the bacteria are also becoming available worldwide. PCV15 is similar to PCV13 and protects against two additional types of the bacteria so may offer more protection.
This study, which lasts 2 months and is funded by Merck Sharp \& Dohme (MSD), aims to assess if using PCV15 can protect against "carriage". To do this, investigators will use a well-established method already used with more than 2,000 people safely in other research. This involves "challenging" volunteers by putting a small amount of the pneumococcus bacteria into their noses. In this study, before they are challenged, volunteers will either be vaccinated with the real PCV15 vaccine or a dummy ("placebo"). The Investigators will then be able to compare the two groups to find out who the vaccine protected and who it did not.
After the study everyone who takes part and fit into certain criteria will be given antibiotics to clear the pneumococcus colonisation. They will also be regularly monitored during the study to ensure their safety.
A very small number of volunteers will be asked to have a biopsy to collect tissue samples from inside their nose before and after being vaccinated with PCV15. This will help researchers to understand more about how the immune system responds to the vaccine.
The information gain in this project will help the investigators to understand how exactly PCV15 vaccine protects people against pneumococcus. This means that this vaccine and future pneumococcal vaccines will be improved to protect many lives in future around the world.
Read the detailed description
This is a Phase IV Double Blind (participant and observer) Placebo Controlled Randomised Controlled Trial (DBRCT) that will assess the superiority of PCV15 against placebo in healthy adults 18-50 years old exposed to an Experimental Human Pneumococcal Challenge (EHPC). Participants will be randomised 1:1 to receive PCV15 or placebo. We estimate a colonisation rate of 60% for the placebo group (84 participants with available endpoints, or up to 106 participants enrolled after adjusting for 20% attrition).
One month following randomisation and vaccination with PCV15 or placebo, all participants will be intranasally inoculated with Streptococcus pneumoniae serotype 3 (SPN3). Participants will be inoculated with a pure culture of a well-characterised, fully sequenced amoxicillin-sensitive pneumococcal serotype 3 (Clade Ia, strain LIV014-S3). Follow-up for 28 days will occur in the clinic with assessment of laboratory measures of the acquisition of nasal pneumococcal colonisation and of immune response after which participants will be required to take a 5-day course of antibiotics. Participants will be considered enrolled into the trial at vaccination.
Exploratory Nasal Biopsy cohort: From the 106 participants enrolled, 5 participants (not included in the primary endpoint sample size) will be asked to consent for a nasal biopsy procedure during screening visit and a second nasal biopsy 28 days after PCV15 vaccination. This cohort will not be blinded as only PCV15 will be provided. These participants wil not be inoculated and the study will terminate after the second biopsy visit (28 after vaccination).
The study is sponsored by the University of Oxford with two sites: Oxford (Centre for Clinical Vaccinology and Tropical Medicine) and Liverpool (Liverpool School of Tropical Medicine). The Experimental Human Pneumococcal Challenge model is well established on both sites.
- Conditions
- Pneumococcal Disease, Pneumococcal Carriage
- Being tested
- PCV15, Streptococcus pneumoniae serotype 3, Placebo
- Keywords
- Streptococcus pneumoniae, Experimental Human Pneumococcal Challenge, Pneumococcal carriage, PCV15, VAXNEUVANCE, SPN3
- Medical subject headings
- Pneumococcal Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PCV15Biological
Also called VAXNEUVANCE
VAXNEUVANCE (Merck, Sharp \& Dohme LLC, a subsidiary of Merck \& Co, Inc., Rahway, NJ, USA [MSD]) is a 15-valent PCV containing capsular polysaccharides from serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F, 22F, and 33F adjuvanted with aluminium phosphate.
Streptococcus pneumoniae serotype 3Biological
Also called SPN3, pneumococcus serotype 3
Streptococcus pneumoniae SPN3 (Clade Ia, strain LIV014-S3) - Single inoculation at 80,000 colony-forming unit (CFU)/naris, 28 days after vaccination.
PlaceboBiological
Also called Saline Placebo, 0.9% Sodium Chloride
The placebo consists of 0.9% sodium chloride for injection
| Study group | Role | What they receive |
|---|---|---|
| PCV-15 Vaccination | Experimental | One dose (0.5 ml) of PCV-15 is to be given Intramuscularly (IM) into the deltoid region of the arm at day 0. Receives: Biological: PCV15; Biological: Streptococcus pneumoniae serotype 3 |
| Placebo | Placebo comparator | 0.9% saline is to be given Intramuscularly (IM) into the deltoid region of the arm at day 0. Receives: Biological: Streptococcus pneumoniae serotype 3; Biological: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Presence or absence of experimental SPN3 colonisation acquisition
Presence or absence of SPN3 bacteria detected by microbiological culture in nasal wash samples for 28 days after experimental SPN3 inoculation at 1-month post PCv15 vaccination compared with placebo.
Measured: Days 2, 7, 14 and 28 following experimental challenge
Secondary outcomes (3)
Density of experimental SPN3 colonisation
To determine the density CFU/ml of experimental SPN3 colonisation for 28 days following EHPC at 1-month post PCV15 vaccination by microbiological culture and molecular methods from nasal wash samples
Measured: Days 2, 7, 14 and 28 following experimental challenge
Duration of experimental SPN3 colonisation
To determine the duration of experimental SPN3 colonisation for 28 days following EHPC at 1-month post PCV15 vaccination by classical culture and molecular methods from NW.
Measured: Days 2, 7, 14 and 28 following experimental challenge
Vaccine-induced immune responses
To compare vaccine-induced immune responses (antibody, antibody activity and B cells populations) to those who receive PCV15 versus control before and after experimental SPN3 challenge.
Measured: Days 7 and 23 following vaccination and 2, 7, 14 and 28 following experimental challenge
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Dec 2024
- Study start24 Feb 2025
- Primary completionDec 2025 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Pneumococcal DiseaseStudies of the same condition, open and under way.
- More trials run by University of OxfordThe sponsor's other registered studies.
- 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 4
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 106 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Oxford
- Sponsor type
- University, hospital or other
- Collaborators
- Liverpool School of Tropical Medicine, United Kingdom, Oxford University Hospitals NHS Trust
- Responsible party
- Sponsor
- Investigators
- Simon Drysdale, MRCPCH, PhD, PgDip PID, FRCPH, Principal investigator, University of OxfordDaniela M Ferreira, PhD, Principal investigator, University of Oxford
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06731374
- Sponsor's protocol ID
- OVG 2024/02
- Other IDs
- MISP 101865
- Acronym
- RATIONALE-15
- Status last verified
- Nov 2024
- First submitted
- 2 Dec 2024
- Last updated
- 15 Apr 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Macedo BR, Solorzano C, Hyder-Wright A, Lustosa Martinelli J, Robinson H, Brito-Mutunayagam S, Urban BC, Codreanu T, Elterish F, Mitsi E, Howard A, El Safadi D, Tanha K, Liu X, Mazur O, Ramasamy MN, Collins A, Ferreira DM, Drysdale SB. Protocol for a phase IV, Experimental Human Pneumococcal Challenge (EHPC) model to investigate Streptococcus pneumoniae serotype 3 (SPN3) colonisation following PCV15, a double-blind randomised controlled trial in healthy participants aged 18-50 years in the UK (RATIONALE-15). BMJ Open. 2025 Nov 24;15(11):e106028. doi: 10.1136/bmjopen-2025-106028.
PubMed 41290307
Study at a glance
From the registry record, last updated by the sponsor on 15 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase IV, Experimental Human Pneumococcal Challenge (EHPC) Model to Investigate Streptococcus Pneumoniae Serotype 3 (SPN3) Colonisation Following PCV15, a Double Blind Randomised Controlled Trial (DBRCT) in Healthy Participants Aged 18 - 50 Years in the UK.
- ClinicalTrials.gov ID
- NCT06731374
- Acronym / sponsor ID
- RATIONALE-15 / OVG 2024/02
- Conditions
- Pneumococcal Disease, Pneumococcal Carriage
- Keywords
- Streptococcus pneumoniae, Experimental Human Pneumococcal Challenge, Pneumococcal carriage, PCV15, VAXNEUVANCE, SPN3
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 106 participants (estimated)
- Lead sponsor
- University of OxfordUniversity, hospital or other
- Collaborators
- Liverpool School of Tropical Medicine, United Kingdom, Oxford University Hospitals NHS Trust
- Study start
- 24 Feb 2025 (actual)
- Primary completion
- Dec 2025 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 12 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Streptococcus pneumoniae (pneumococcus) is a bacterium that causes just under four million serious infections every year. It is normal for pneumococcus bacteria to live in the noses of healthy adults and children as part of the nasal microflora without causing harm. This is called "carriage". But the bacteria can still be passed on to other people. If they are at-risk, for example elderly, or very young, or have pre-existing health conditions, the pneumococcus bacteria can cause pneumonia, which can cause serious life-threatening illness.
Pneumococcus bacteria are surrounded by a sugar capsule. But the capsule does not always have the same components. As a result, the bacteria are classified into more than 100 different types. To make them effective, the vaccines that are currently available contain the sugar capsules of the most common pneumococcal types that cause disease.
One such vaccine - PCV13 - has been effective globally in protecting against pneumococcus disease. It works because it controls the "carriage" (how a person carries the bacteria in their nose) of 13 types of the bacteria. Vaccines giving protection against other types of the bacteria are also becoming available worldwide. PCV15 is similar to PCV13 and protects against two additional types of the bacteria so may offer more protection.
This study, which lasts 2 months and is funded by Merck Sharp \& Dohme (MSD), aims to assess if using PCV15 can protect against "carriage". To do this, investigators will use a well-established method already used with more than 2,000 people safely in other research. This involves "challenging" volunteers by putting a small amount of the pneumococcus bacteria into their noses. In this study, before they are challenged, volunteers will either be vaccinated with the real PCV15 vaccine or a dummy ("placebo"). The Investigators will then be able to compare the two groups to find out who the vaccine protected and who it did not.
After the study everyone who takes part and fit into certain criteria will be given antibiotics to clear the pneumococcus colonisation. They will also be regularly monitored during the study to ensure their safety.
A very small number of volunteers will be asked to have a biopsy to collect tissue samples from inside their nose before and after being vaccinated with PCV15. This will help researchers to understand more about how the immune system responds to the vaccine.
The information gain in this project will help the investigators to understand how exactly PCV15 vaccine protects people against pneumococcus. This means that this vaccine and future pneumococcal vaccines will be improved to protect many lives in future around the world.
Detailed description
This is a Phase IV Double Blind (participant and observer) Placebo Controlled Randomised Controlled Trial (DBRCT) that will assess the superiority of PCV15 against placebo in healthy adults 18-50 years old exposed to an Experimental Human Pneumococcal Challenge (EHPC). Participants will be randomised 1:1 to receive PCV15 or placebo. We estimate a colonisation rate of 60% for the placebo group (84 participants with available endpoints, or up to 106 participants enrolled after adjusting for 20% attrition).
One month following randomisation and vaccination with PCV15 or placebo, all participants will be intranasally inoculated with Streptococcus pneumoniae serotype 3 (SPN3). Participants will be inoculated with a pure culture of a well-characterised, fully sequenced amoxicillin-sensitive pneumococcal serotype 3 (Clade Ia, strain LIV014-S3). Follow-up for 28 days will occur in the clinic with assessment of laboratory measures of the acquisition of nasal pneumococcal colonisation and of immune response after which participants will be required to take a 5-day course of antibiotics. Participants will be considered enrolled into the trial at vaccination.
Exploratory Nasal Biopsy cohort: From the 106 participants enrolled, 5 participants (not included in the primary endpoint sample size) will be asked to consent for a nasal biopsy procedure during screening visit and a second nasal biopsy 28 days after PCV15 vaccination. This cohort will not be blinded as only PCV15 will be provided. These participants wil not be inoculated and the study will terminate after the second biopsy visit (28 after vaccination).
The study is sponsored by the University of Oxford with two sites: Oxford (Centre for Clinical Vaccinology and Tropical Medicine) and Liverpool (Liverpool School of Tropical Medicine). The Experimental Human Pneumococcal Challenge model is well established on both sites.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| PCV-15 Vaccination | Experimental | Biological: PCV15, Biological: Streptococcus pneumoniae serotype 3One dose (0.5 ml) of PCV-15 is to be given Intramuscularly (IM) into the deltoid region of the arm at day 0. |
| Placebo | Placebo comparator | Biological: Streptococcus pneumoniae serotype 3, Biological: Placebo0.9% saline is to be given Intramuscularly (IM) into the deltoid region of the arm at day 0. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Adults between 18 to 50 years old (inclusive) at the time of enrolment.
- Medically healthy, such that according to investigator judgement, hospitalisation within the study period is not anticipated, and the participant appears likely to be able to remain a study participant through to the end of protocol-specified follow-up. Planned elective procedures for pre-existing conditions may be allowable.
- Fluent spoken English - to ensure a comprehensive understanding of the research project and their proposed involvement.
- Able to attend the scheduled visits and to comply with all study procedures, including internet access for the recording of electronic diary after inoculation.
- Willing and able to give informed consent for participation in the study.
Key exclusion criteria (49 listed)
- Research Participants:
- Vaccination (self-reported or confirmed from GP questionnaire or medical records/summary if deemed necessary at clinician discretion):
- Allergy:
- Health History (self-reported or confirmed from GP questionnaire or medical records/summary if deemed necessary): moderate ill health including but not limited to:
- Taking Medications:
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 |
|---|---|---|
| PCV15Also: VAXNEUVANCEVAXNEUVANCE (Merck, Sharp \& Dohme LLC, a subsidiary of Merck \& Co, Inc., Rahway, NJ, USA [MSD]) is a 15-valent PCV containing capsular polysaccharides from serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F, 22F, and 33F adjuvanted with aluminium phosphate. | Biological | PCV-15 Vaccination |
| Streptococcus pneumoniae serotype 3Also: SPN3, pneumococcus serotype 3Streptococcus pneumoniae SPN3 (Clade Ia, strain LIV014-S3) - Single inoculation at 80,000 colony-forming unit (CFU)/naris, 28 days after vaccination. | Biological | PCV-15 Vaccination, Placebo |
| PlaceboAlso: Saline Placebo, 0.9% Sodium ChlorideThe placebo consists of 0.9% sodium chloride for injection | Biological | Placebo |
Primary outcome
Presence or absence of experimental SPN3 colonisation acquisition
Time frame: Days 2, 7, 14 and 28 following experimental challenge
Presence or absence of SPN3 bacteria detected by microbiological culture in nasal wash samples for 28 days after experimental SPN3 inoculation at 1-month post PCv15 vaccination compared with placebo.
3 secondary outcomes
Density of experimental SPN3 colonisation
Time frame: Days 2, 7, 14 and 28 following experimental challenge
Duration of experimental SPN3 colonisation
Time frame: Days 2, 7, 14 and 28 following experimental challenge
Vaccine-induced immune responses
Time frame: Days 7 and 23 following vaccination and 2, 7, 14 and 28 following experimental challenge
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Apr 2025.
- Derived from this study: PubMed 41290307Macedo BR, Solorzano C, Hyder-Wright A, Lustosa Martinelli J, Robinson H, Brito-Mutunayagam S, Urban BC, Codreanu T, Elterish F, Mitsi E, Howard A, El Safadi D, Tanha K, Liu X, Mazur O, Ramasamy MN, Collins A, Ferreira DM, Drysdale SB. Protocol for a phase IV, Experimental Human Pneumococcal Challenge (EHPC) model to investigate Streptococcus pneumoniae serotype 3 (SPN3) colonisation following PCV15, a double-blind randomised controlled trial in healthy participants aged 18-50 years in the UK (RATIONALE-15). BMJ Open. 2025 Nov 24;15(11):e106028. doi: 10.1136/bmjopen-2025-106028.
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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.
Simon Drysdale, MRCPCH, PhD, PgDip PID, FRCPH principal investigator
University of Oxford
Daniela M Ferreira, PhD principal investigator
University of Oxford
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing PCV15 and Streptococcus pneumoniae serotype 3 in people with Pneumococcal Disease and Pneumococcal Carriage, run by University of Oxford at 2 sites in United Kingdom.
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 9 inclusion and 49 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: looking for participants now, as of the sponsor's last update on 15 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Carla Solorzano-Gonzalez, PhD (+44 1865 611400, Carla.SolorzanoGonzalez@paediatrics.ox.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Presence or absence of experimental SPN3 colonisation acquisition (time frame: Days 2, 7, 14 and 28 following experimental challenge). 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 NCT06731374, 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 15 Apr 2025.