Home › Trials › NCT05543616

Learning about a new COVID-19 vaccine for healthy children

A MASTER PHASE 1/2/3 PROTOCOL TO INVESTIGATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF VARIANT-ADAPTED BNT162b2 RNA-BASED VACCINE CANDIDATE(S) IN HEALTHY CHILDREN

Phase2; Phase3 Interventional BioNTech SE · NCT05543616

This study is testing a new COVID-19 vaccine in healthy children under 5 years old to see how safe it is and how well it works.

Quick facts

PhasePhase2; Phase3
Study typeInterventional
Enrollment3692 (estimated)
Ages6 Months to 11 Years
SexAll
SponsorBioNTech SE Industry-sponsored
Drugs / interventionspalivizumab, prednisone
Locations125 sites (Birmingham, Alabama and 124 other locations)
Trial IDNCT05543616 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the safety, side effects, and immune responses of a variant-adapted RNA vaccine in healthy children. It consists of five substudies based on age and prior COVID-19 vaccination history, where participants will receive varying doses of the vaccine. The trial includes both Phase 2 and Phase 3 components, focusing on children aged 6 months to less than 5 years. Participants will be monitored for their immune response and any adverse effects following vaccination.

Who should consider this trial

Good fit: Ideal candidates are healthy children aged 6 months to less than 5 years who have not previously received a COVID-19 vaccine.

Not a fit: Patients with a history of severe allergic reactions to vaccines or those with immunocompromised conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this vaccine could provide enhanced protection against COVID-19 variants in young children.

How similar studies have performed: Other studies have shown success with similar RNA vaccine approaches, particularly in adult populations, suggesting potential for effectiveness in children.

Eligibility criteria

Show full inclusion / exclusion criteria 
Substudy A

Inclusion Criteria:

* Phase 1: Healthy male or female participants ≥6 months to \<4 years 3 months of age, at the time of randomization.
* Phase 2/3: Healthy male or female participants ≥6 months to \<5 years of age at the time of randomization/enrollment.

Exclusion Criteria:

* Previous or current diagnosis of multisystem inflammatory syndrome in children (MIS-C).
* History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
* Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination, or individuals who receive treatment with immunosuppressive therapy.
* Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention, including but not limited to systemic lupus erythematosus. Note: Stable type 1 diabetes and hypothyroidism are permitted.
* Any history of myocarditis or pericarditis.
* Previous vaccination with any COVID-19 vaccine.
* Receipt of systemic treatment with known immunosuppressant medications (including cytotoxic agents or systemic corticosteroids, eg, for cancer) or radiotherapy, within 60 days before enrollment through the conclusion of the study. Systemic corticosteroids (≥2 mg/kg of body weight or ≥20 mg/day of prednisone or equivalent for persons who weigh \>10 kg) for ≥14 days is prohibited from 28 days prior to enrollment through 28 days after administration of study intervention.
* Receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies (except palivizumab), from 60 days before study intervention administration, or receipt of any passive antibody therapy specific to COVID-19 from 90 days before study intervention administration, or planned receipt throughout the study.

Substudy B

Inclusion Criteria:

- Healthy male or female participants = ≥6 months to \<5 years of age, at the time of enrollment.

Exclusion Criteria:

* Previous or current diagnosis of MIS-C.
* History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
* Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination, or individuals who receive treatment with immunosuppressive therapy.
* Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention, including but not limited to systemic lupus erythematosus.
* Prior receipt of any COVID 19 vaccine other than BNT162b2.
* Receipt of systemic treatment with known immunosuppressant medications (including cytotoxic agents or systemic corticosteroids, eg, for cancer) or radiotherapy, within 60 days before enrollment through the conclusion of the study. Systemic corticosteroids (≥2 mg/kg of body weight or ≥20 mg/day of prednisone or equivalent for persons who weigh \>10 kg) for ≥14 days is prohibited from 28 days prior to enrollment through 28 days after administration of study intervention.
* Receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies (except palivizumab), from 60 days before study intervention administration, or receipt of any passive antibody therapy specific to COVID-19 from 90 days before study intervention administration, or planned receipt throughout the study.

Substudy C

Inclusion Criteria:

- Healthy male or female participants ≥6 months to \<5 years of age, at the time of randomization/enrollment.

Exclusion Criteria:

* Previous or current diagnosis of MIS-C.
* History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
* Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination, or individuals who receive treatment with immunosuppressive therapy.
* Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention, including but not limited to systemic lupus erythematosus.
* Prior receipt of any COVID 19 vaccine other than BNT162b2.
* Receipt of systemic treatment with known immunosuppressant medications (including cytotoxic agents or systemic corticosteroids, eg, for cancer) or radiotherapy, within 60 days before enrollment through the conclusion of the study. Systemic corticosteroids (≥2 mg/kg of body weight or ≥20 mg/day of prednisone or equivalent for persons who weigh \>10 kg) for ≥14 days is prohibited from 28 days prior to enrollment through 28 days after administration of study intervention.
* Receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies (except palivizumab), from 60 days before study intervention administration, or receipt of any passive antibody therapy specific to COVID-19 from 90 days before study intervention administration, or planned receipt throughout the study.

Substudy D

Inclusion Criteria:

- Healthy male or female participants ≥5 years to \<12 years of age, at the time of enrollment.

Exclusion Criteria:

* Previous or current diagnosis of MIS-C.
* History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
* Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination, or individuals who receive treatment with immunosuppressive therapy.
* Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention, including but not limited to systemic lupus erythematosus.
* Female who is pregnant or breastfeeding.
* Prior receipt of any COVID 19 vaccine other than BNT162b2.
* Receipt of systemic treatment with known immunosuppressant medications (including cytotoxic agents or systemic corticosteroids, eg, for cancer) or radiotherapy, within 60 days before enrollment through the conclusion of the study. Systemic corticosteroids (≥2 mg/kg of body weight or ≥20 mg/day of prednisone or equivalent for persons who weigh \>10 kg) for ≥14 days is prohibited from 28 days prior to enrollment through 28 days after administration of study intervention.
* Receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies (except palivizumab), from 60 days before study intervention administration, or receipt of any passive antibody therapy specific to COVID-19 from 90 days before study intervention administration, or planned receipt throughout the study.

Substudy E

Inclusion Criteria:

- Healthy male or female participants ≥2 years to \<12 years of age, at the time of enrollment.

Exclusion Criteria:

* Previous or current diagnosis of MIS-C.
* History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
* Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination, or individuals who receive treatment with immunosuppressive therapy.
* Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention, including but not limited to systemic lupus erythematosus.
* Any history of myocarditis or pericarditis.
* Female who is pregnant or breastfeeding.
* Previous vaccination with any COVID 19 vaccine.
* Receipt of systemic treatment with known immunosuppressant medications (including cytotoxic agents or systemic corticosteroids, eg, for cancer) or radiotherapy, within 60 days before enrollment through the conclusion of the study. Systemic corticosteroids (≥2 mg/kg of body weight or ≥20 mg/day of prednisone or equivalent for persons who weigh \>10 kg) for ≥14 days is prohibited from 28 days prior to enrollment through 28 days after administration of study intervention.
* Receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies (except palivizumab), from 60 days before study intervention administration, or receipt of any passive antibody therapy specific to COVID-19 from 90 days before study intervention administration, or planned receipt throughout the study.

Where this trial is running

Birmingham, Alabama and 124 other locations

+75 more sites — see ClinicalTrials.gov for the full list.

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions SARS-CoV-2 VirusSevere Acute Respiratory Syndrome Coronavirus 2COVID-19CoronavirusVaccineSARS-CoV-2RNA Vaccine
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.