PCV24 vaccine for infants aged 2 to 23 months

A Randomized, Double-blind, Positive Controlled Phase Ib Clinical Trial to Evaluate the Safety and Immunogenicity of 24-valent Pneumococcal Conjugate Vaccine in Children Aged 2 (Minimum 42 Days)-23 Months

This will test whether the new 24‑valent PCV24 vaccine is safe and produces protective immune responses in healthy infants aged 2 to 23 months, compared with the standard Prevnar13 vaccine.

Quick facts

• Phase: PHASE1
• Study type: Interventional
• Enrollment: 180 (estimated)
• Ages: 42 Days to 23 Months
• Sex: All
• Sponsor: Sinovac Biotech Co., Ltd (industry)
• Locations: 2 sites (Jinan, Shandong and 1 other locations)
• Trial ID: NCT06800261 on ClinicalTrials.gov

What this trial studies

A randomized, double-blind, positive-controlled Phase 1b trial will enroll at least 180 healthy Chinese infants aged 2 months (≥42 days) to 23 months and randomize them 1:1 to receive either Sinovac's PCV24 or Pfizer's Prevnar13. The primary goals are to monitor safety and measure immune responses to the 24 pneumococcal serotypes included in PCV24. Safety will be tracked through observation of adverse events and serious adverse events, and immunogenicity will be measured by blood antibody levels at scheduled visits. The trial is conducted at provincial and county CDC sites in Shandong province, China.

Who should consider this trial

Good fit: Healthy infants aged 2 months (≥42 days) to 23 months who have not previously received any pneumococcal vaccine and whose legal guardians can provide consent and vaccination records are ideal candidates.

Not a fit: Infants who have previously received a pneumococcal vaccine, have a history of invasive pneumococcal disease, serious vaccine allergies, low birth weight or prematurity (for those under 12 months), or other listed exclusions are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, PCV24 could offer broader protection against additional pneumococcal serotypes in young children than currently available vaccines.

How similar studies have performed: Other higher‑valent pneumococcal conjugate vaccines have demonstrated immunogenicity and acceptable safety profiles in children, but PCV24 is a new formulation that has not yet been widely tested in this age group.

Eligibility criteria

Inclusion Criteria:

1. Healthy infants who are aged 2 months (42-89 days), 7-11 months, 12-23 months;
2. Participants' guardian provides legal identity document and participants' vaccination record;
3. Participants' guardian understands and voluntarily signs the informed consent form;
4. Follow all study procedures and stay in contact during the study.

Exclusion Criteria:

1. Received any pneumococcal vaccine prior to enrollment;
2. History of invasive pneumococcal diseases or other pneumococcal diseases caused by Streptococcus pneumoniae, as confirmed by laboratory tests;
3. History of severe adverse reactions to the vaccine or vaccine components, or history of allergy, such as urticaria, dyspnea, angioneurotic edema, anaphylactic shock;
4. Low birth weight (\<2.5kg), or premature infant (gestation weeks \< 37 weeks) (applies to infants younger than 12 months);
5. History of abnormal labor during delivery (planned cesarean section is excluded), history of asphyxia rescue and nervous system damage (applies to infants younger than 12 months);
6. Congenital malformations or developmental disorders, genetic defects, severe malnutrition;
7. Have uncontrolled chronic diseases or history of severe diseases, including but not limited to cardiovascular diseases (e.g. congenital heart disease), hematological diseases (e.g. severe anemia), liver and kidney diseases, digestive diseases, respiratory diseases (such as active tuberculosis), malignant tumors and major functional organ transplantation history;
8. Autoimmune diseases, immunodeficiency diseases (including but not limited to systemic lupus erythematosus, rheumatoid arthritis, autoimmune thyroid disease, asplenia, functional asplenia, HIV infection);
9. Diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets level), potential bleeding (history of obvious bleeding, hematoma or bruising after intramuscular injection or venipuncture).
10. Have/have suffered from a serious neurological disorder (epilepsy or convulsions, but febrile convulsion is not an exclusion criteria ) or mental illness or have a family history of such diseases.
11. Consecutively received immunosuppressive therapy (excluding corticosteroid spray therapy for allergic rhinitis and surface corticosteroid therapy for acute non-concurrent dermatitis), or other immunoregulatory therapies, or cytotoxic therapy over 14 days within 6 months before vaccination, or plans to receive such therapies during the study.
12. Received blood products prior to enrollment within 3 months prior to enrollment, or plans to receive such therapies during the study. Receipt of Hepatitis B immunoglobulin one month prior to enrollment is an exception.
13. Received other investigational drugs or vaccines within 30 days prior to enrollment, or plan to receive such drugs or vaccines during the study;
14. Received live attenuated vaccine within 14 days prior to enrollment;
15. Received subunit or inactivated vaccine within 7 days prior to enrollment;
16. Acute diseases or acute onset of chronic diseases within 7 days prior to enrollment, known or potentially active infection;
17. Axillary temperature≥ 37.3 Degree Celsius before vaccination;
18. In the investigator's judgment, the participant has any other factors that make him or her unfit to participate in the clinical trial.

Where this trial is running

Jinan, Shandong and 1 other locations

• Shandong Provincial Center for Disease Control and Prevention — Jinan, Shandong, China (NOT_YET_RECRUITING)
• Shanxian Center for Disease Control and Prevention — Shancheng, Shandong, China (RECRUITING)

Study contacts

• Principal investigator: Qing Xu — Shandong Provincial Center for Disease Control and Prevention
• Study coordinator: Qing Xu

Conditions: Pneumococcal Infectious Disease