A Phase 3 interventional study of PCV21 vaccine and Prevnar 20 vaccine in Pneumococcal Immunization, sponsored by Sanofi. Active, not recruiting at 132 sites in 6 countries. Open to participants aged 42 Days to 89 Days, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-13.
Sponsored by Sanofi · Phase 3, Interventional, and Prevention
This study is a Phase 3, randomized, modified double-blind study which aims to document the safety profile of the PCV21 vaccine (investigational pneumococcal vaccine) compared to a licensed 20-valent pneumococcal conjugate vaccine in infants aged from approximately 2 months (42 to 89 days).
The study duration per participant will be up to approximately 19 months. The study vaccines (either PCV21 or 20vPCV) will be administered at approximately 2, 4, 6 and 12 to 15 months of age. Routine pediatric vaccines will be given as per local recommendations.
There will be 6 study visits:
Visit (V)01, V02 separated from V01 by 60 days, V03 separated from V02 by 60 days, V04 separated from V03 by 30 days, V05 at 12 months of age until 15 months of age, V06 separated from V05 by 30 days.
Sanofi is the lead sponsor of 1,557 studies on the registry; 91 are open to participants now.
Of its 205 completed or terminated interventional studies of FDA-regulated products, 123 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Participants are excluded from the study if any of the following criteria apply:
Note: The above information is not intended to contain all considerations relevant to a potential participation in a clinical trial.
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.
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.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
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.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will be administered via intramuscular injection (IM) a 4-dose PCV21 regimen at approximately 2, 4, 6 and 12 to 15 MoA
Biological: PCV21 vaccine · Biological: M-M-R II vaccine · Biological: Rotarix · Biological: RotaTeq · Biological: Vaxelis vaccine · Biological: Varivax · Biological: Priorix · Biological: VAQTA · Biological: Havrix
Participants will be administered via intramuscular injection (IM) a 4-dose 20vPCV regimen at approximately 2, 4, 6 and 12 to 15 MoA
Biological: Prevnar 20 vaccine · Biological: M-M-R II vaccine · Biological: Rotarix · Biological: RotaTeq · Biological: Vaxelis vaccine · Biological: Varivax · Biological: Priorix · Biological: VAQTA · Biological: Havrix
Pharmaceutical form:Suspension for injection-Route of administration:Intramuscular
Also known as: 515
Pharmaceutical form:Suspension for injection-Route of administration:Intramuscular
Also known as: Prevnar20™
Pharmaceutical form:Powder, lyophilized, for suspension for reconstitution-Route of administration:Subcutaneous or Intramuscular
Also known as: M-M-R™ II
Pharmaceutical form:Solution-Route of administration:Oral
Also known as: Rotarix™
Pharmaceutical form:Solution-Route of administration:Oral
Also known as: RotaTeq™
Pharmaceutical form:Suspension for injection-Route of administration:Intramuscular
Also known as: Vaxelis™
Pharmaceutical form:Powder, lyophilized, for suspension for reconstitution-Route of administration:Subcutaneous or Intramuscular
Also known as: Varivax™
Pharmaceutical form:Lyophilized, for suspension for reconstitution-Route of administration:Subcutaneous
Also known as: Priorix™
Pharmaceutical form:Suspension for Injection-Route of administration:Intramuscular
Also known as: VAQTA™
Pharmaceutical form:Suspension for Injection-Route of administration:Intramuscular
Also known as: Havrix™
Presence of any immediate adverse events (AEs)
Number of participants experiencing solicited and unsolicited immediate AEs
Time frame: Within 30 minutes after each vaccination
Presence of solicited injection site and systemic reactions through 7 days after each vaccine injection
Number of participants experiencing solicited injection site and systemic reactions
Time frame: Through 7 days after each vaccine injection
Presence of unsolicited (spontaneously reported) injection site reactions and unsolicited systemic AEs through 30 days after each vaccine injection
Number of participants experiencing unsolicited injection site reactions and unsolicited systemic AEs
Time frame: Through 30 days after each vaccine injection
Presence of serious adverse events (SAEs) throughout the study (through 6 months post- last vaccine injection)
Number of participants experiencing SAEs
Time frame: Throughout the study (through 6 months post-last vaccine injection), approximately 19 months
Presence adverse events of special interest (AESIs) throughout the study (through 6 months post- last vaccine injection)
Number of participants experiencing AESIs
Time frame: Throughout the study (through 6 months post-last vaccine injection), approximately 19 months
Showing the first 100 of 132 sites across 6 countries. Choose a country and city above to see the rest.
Plan to share: Yes — Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org
Started Feb 2025 (actual). Primary completion is estimated for Oct 2027, 32 months after the start.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Pneumococcal 21-Valent Conjugate Vaccine