A Phase 2 interventional study of Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3) and Sabin Monovalent Oral Poliomyelitis Vaccine Type 3 (mOPV3) in Poliomyelitis, sponsored by PATH. Recruiting at 3 sites in Panama. Open to participants aged 1 Day to 4 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-11.
Sponsored by PATH · Phase 2, Interventional, and Prevention
The purpose of this clinical trial is to assess the safety and tolerability (primary objective), immunogenicity (primary and secondary objectives), fecal shedding of vaccine viruses (secondary objective) and the potential for neurovirulence of shed virus (secondary objective) of a novel oral polio type 3 vaccine, nOPV3, as compared to Sabin monovalent type 3 vaccine controls (mOPV3), in healthy young children (192 subjects), infants (860 subjects), and neonates (480 subjects).
This multicentered, 12-arm phase 2 study will be the first pediatric evaluation of nOPV3 in healthy young children, infants, and newborns. This trial will be initiated once results in the adult phase 1 study of nOPV3 indicate that there are no safety concerns, and that the vaccine elicits demonstrable immunogenicity. Additionally, prior to enrolling into cohort 2, the adult phase 1 data must show no concerning signals of reversion of attenuating sites from a subset of Next Generation Sequencing.
This study is intended to provide critical data on safety, immunogenicity, and genetic stability, as well as to demonstrate the vaccine's ability to reduce fecal shedding following a challenge with the Sabin type 3 strain.
Enrollment in this pediatric study will be staggered into three age-descending cohorts of 6 treatment groups of escalated target dose levels for the nOPV3 vaccine: cohort 1 composed of 192 healthy young children 1 to \<5 years of age who have completed their full routine polio immunization series; cohort 2 composed of 860 healthy infants 6 weeks of age not previously vaccinated (OPV/IPV) who will be primed with a dose of inactivated poliomyelitis vaccine (IPV) prior to OPV3 vaccination [a subset, of the infants (n=360) will also receive the challenge virus]; and cohort 3, composed of 480 healthy poliomyelitis unvaccinated neonates (day of birth +3 days).
Progression into the next cohort and groups within cohorts will depend on safety evaluations of the prior Phase 1 adult trial and Day 8 safety evaluation of the previous groups in prior cohorts in the study.
274 studies on the registry are indexed under Poliomyelitis; 18 are open to participants now.
This study's planned enrollment of 1,532 is above the median of 476 across 249 interventional studies indexed under Poliomyelitis.
Browse Poliomyelitis studies →PATH is the lead sponsor of 113 studies on the registry; 7 are open to participants now.
Of its 10 completed or terminated interventional studies of FDA-regulated products, 10 (100%) have results posted.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria
Inclusion Criteria for all participants:
Inclusion Criteria for cohort 1 participants only:
Inclusion Criteria for cohort 2 participants only:
Inclusion Criteria for Cohort 3 participants only:
Exclusion Criteria
Exclusion Criteria for all participants:
Presence of fever on the day of enrollment/first study vaccination (axillary temperature
≥37.5˚C)-(Temporary exclusion for cohorts 1 and 2). If resolved in 48 hrs., can be enrolled.
Exclusion Criteria for cohort 2 and 3 participants only:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
48 young children aged 1 to \<5 years will receive 2 doses of nOPV3 at a dose level of 10\^5.5 CCID50 on Day 1 and Day 29
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3)
48 young children aged 1 to \<5 years will receive 2 doses of nOPV3 at a dose level of 10\^6.0 CCID50 on Day 1 and Day 29
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3)
48 young children aged 1 to \<5 years will receive 2 doses of nOPV3 at a dose level of 10\^6.5 CCID50 on Day 1 and Day 29
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3)
48 young children aged 1 to \<5 years will receive 2 doses of mOPV3 at a dose level of ≥ 10\^5.8 CCID50 on Day 1 and Day 29
Biological: Sabin Monovalent Oral Poliomyelitis Vaccine Type 3 (mOPV3)
240 infants aged 6 weeks (+6 days) will receive 1 dose of IPV on Day 1, then 2 doses of nOPV3 at a dose level of 10\^5.5 CCID50 on Day 29 and Day 57, and a challenge dose of mOPV on Day 113.
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3) · Biological: Sabin Monovalent Oral Poliomyelitis Vaccine Type 3 (mOPV3)
240 infants aged 6 weeks (+6 days) will receive 1 dose of IPV on Day 1, then 2 doses of nOPV3 at a dose level of 10\^6.0 CCID50 on Day 29 and Day 57, and a challenge dose of mOPV on Day 113.
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3) · Biological: Sabin Monovalent Oral Poliomyelitis Vaccine Type 3 (mOPV3)
140 infants aged 6 weeks (+6 days) will receive 1 dose of IPV on Day 1, then 2 doses of nOPV3 at a dose level of 10\^6.5 CCID50 on Day 29 and Day 57, and a challenge dose of mOPV on Day 113.
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3) · Biological: Sabin Monovalent Oral Poliomyelitis Vaccine Type 3 (mOPV3)
240 infants aged 6 weeks (+6 days) will receive 1 dose of IPV on Day 1, then 2 doses of mOPV3 at a dose level of ≥ 10\^5.8 CCID50 on Day 29 and Day 57, and a challenge dose of mOPV on Day 113.
Biological: Sabin Monovalent Oral Poliomyelitis Vaccine Type 3 (mOPV3)
120 neonates (day of birth + 3 days) will receive 2 doses of nOPV3 at a dose level of 10\^5.5 CCID50 on Day 1 and Day 29.
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3)
120 neonates (day of birth + 3 days) will receive 2 doses of nOPV3 at a dose level of 10\^6.0 CCID50 on Day 1 and Day 29.
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3)
120 neonates (day of birth + 3 days) will receive 2 doses of nOPV3 at a dose level of 10\^6.5 CCID50 on Day 1 and Day 29.
Biological: Novel Live Attenuated Type 3 Oral Poliomyelitis Vaccine (nOPV3)
120 neonates (day of birth + 3 days) will receive 2 doses of mOPV3 at a dose level of ≥ 10\^5.8 CCID50 on Day 1 and Day 29
Biological: Sabin Monovalent Oral Poliomyelitis Vaccine Type 3 (mOPV3)
The nOPV3 vaccine containing approximately 10\^5.5, 10\^6.0, or 10\^6.5 CCID50 per dose.
The Sabin Monovalent Oral Poliomyelitis Vaccine Type 3 control and challenge vaccine (mOPV3) containing ≥ 10\^5.8 CCID50 per dose.
Frequency of serious adverse events (SAEs)
Serious adverse event is any adverse event that results in any of the following outcomes: 1. Death 2. Is life-threatening (life-threatening means that the study participant was, in the opinion of the site PIs or PATH, at risk of death at the time of the event; it does not refer to an event which hypothetically might have caused death if it were more severe). 3. Requires inpatient hospitalization or prolongation of existing hospitalization. 4. Results in persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions. 5. Congenital abnormality or birth defect. 6. Important medical event that may not result in one of the above outcomes but may jeopardize the health of the study participant and require medical or surgical intervention to prevent one of the outcomes listed in the above definition of serious adverse event.
Time frame: Up to last visit for last subject, around 18 months
Frequency of solicited adverse events (AEs) for 7 days (day of vaccination and 6 following days) after each vaccination
Solicited AEs are pre-specific AEs that are common or known to be associated with vaccination that are actively monitored as potential indicators of vaccine reactogenicity. The following specific solicited AEs will be monitored for this trial: Fever (axillary temperature ≥ 37.5°C) Vomiting Diarrhea Irritability Decreased feeding or appetite Fatigue or decreased activity
Time frame: Vaccination to 7 days post vaccination
Frequency of unsolicited AEs for 28 days (day of vaccination and 27 following days) after each vaccination
Unsolicited AEs are any AEs reported spontaneously by the participant's parent, observed by the study personnel during study visits or identified during review of medical records or source documents. In the absence of a diagnosis, abnormal physical examination findings or abnormal clinical safety laboratory test results that are assessed by the investigator to be clinically significant will be reported as an AE.
Time frame: From vaccination to 28 days post vaccination
Post-vaccination frequency of seroconversion of type 3 anti-polio serum neutralizing antibody (NAb) in infants.
For previously vaccinated cohorts, seroconversion will be defined as a minimum 4-fold rise in titer relative to the baseline value among those initially seropositive.
Time frame: 28 days post second vaccination
Post-vaccination frequency of seroconversion of type 3 anti-polio serum NAb
For previously vaccinated cohorts, seroconversion will be defined as a minimum 4-fold rise in titer relative to the baseline value among those initially seropositive and for unvaccinated neonates, seroconversion will be defined as a minimum 4-fold higher antibody titer relative to the expected level of maternal antibody.
Time frame: Baseline and 28 days post vaccination (Day 1 and Day 29 for neonates; Day 29,Day 57 and Day 85 for infants; Day 1, Day 29 and Day 57 young children)
Median type 3 anti-polio serum NAb titers
Elicited by nOPV3, compared to that of mOPV3, following one or two doses in healthy young children, infants, and neonates.
Time frame: Baseline and 28 days post vaccination (Day 1, Day 29 and Day 57 for young children and neonates; Day 29, Day 57 and Day 85 for infants)
Type 3 anti-polio serum NAb Geometric Mean Titer (GMT)
Elicited by nOPV3, compared to that of mOPV3, following one or two doses in healthy young children, infants, and neonates.
Time frame: Baseline and 28 days post vaccination (Day 1, Day 29 and Day 57 for young children and neonates;Day 29, Day 57 and Day 85 for infants)
Post-vaccination GMT ratios of type 3 anti-polio serum NAb, adjusted for baseline immunity
Elicited by nOPV3, compared to that of mOPV3, following one or two doses in healthy young children, infants, and neonates.
Time frame: Baseline and 28 days post vaccination (Day 1, Day 29 and Day 57 for young children and neonates; Day 29, Day 57 and Day 85 for infants)
Seroprotection rate, defined as type 3 anti-polio serum NAb reciprocal titer ≥ 8
Elicited by nOPV3, compared to that of mOPV3, following one or two doses in healthy young children, infants, and neonates.
Time frame: Baseline and 28 days post vaccination (Day 1, Day 29 and Day 57 for young children and neonates; Day 29, Day 57 and Day 85 for infants)
Geometric mean fold rise (GMFR) in NAb titer relative to baseline for post-dose-1 and relative to post-dose-1 for post-dose-2.
Elicited by nOPV3, compared to that of mOPV3, in healthy young children, infants,and neonates.
Time frame: Baseline and 28 days postvaccination (Day 1, Day 29 and Day 57 for young children and neonates; Day 29, Day57 and Day 85 for infants)
Proportion of participants shedding type 3 poliovirus at any and at each post-vaccination stool collection, as assessed by polymerase chain reaction (PCR) in infants
After the initial dose of nOPV3, compared to mOPV3
Time frame: Baseline through to 28 days post initial vaccination (Day 29 through to Day 57 for infants)
Proportion of participants shedding type 3 poliovirus at any and at each post-challenge stool collection, as assessed by PCR in infants
In participants negative for type 3 poliovirus in their last pre-challenge stool sample
Time frame: Day of challenge through to 28 days post challenge (Day 113 through to Day 141, for infants)
Neurovirulence of shed study vaccine virus from select stool samples as measured by a transgenic mouse neurovirulence test in a subset of infants
Within 28 days of an initial nOPV dose and compared to that of mOPV3
Time frame: Baseline through to 28 days post initial vaccination (Day 1 through to Day 29 for neonates)
Plan to share: No
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