24‑valent pneumococcal conjugate vaccine (PCV24) for children aged 2 months to 5 years

A Randomized, Double-blind, Positive-controlled Phase II Clinical Trial to Evaluate the Safety and Immunogenicity of 24-valent Pneumococcal Conjugate Vaccine in Children Aged 2 Months (Minimum 42 Days) to 5 Years

This will test whether Sinovac's 24‑valent pneumococcal vaccine (PCV24) is safe and triggers protective immune responses in children aged 2 months to 5 years, compared with the licensed Prevnar13 vaccine.

Quick facts

• Phase: Phase 2
• Study type: Interventional
• Enrollment: 420 (estimated)
• Ages: 42 Days to 5 Years
• Sex: All
• Sponsor: Sinovac Biotech Co., Ltd (Industry-sponsored)
• Locations: 3 sites (Huanggang, Hubei and 2 other locations)
• Trial ID: NCT07300644 on ClinicalTrials.gov

What this trial studies

This randomized, double‑blind, positive‑controlled Phase 2 trial will enroll at least 420 healthy children aged 2 months (minimum 42 days) to 5 years and randomize them 1:1 to receive either Sinovac PCV24 or the active control Prevnar13. The study will collect safety data and measure immune responses to the vaccine across pre-specified age cohorts. Participants will be followed according to the protocol with scheduled visits and laboratory testing to characterize immunogenicity and adverse events. The trial is sponsored by Sinovac Life Sciences and will be conducted at three district CDC sites in Hubei province, China.

Who should consider this trial

Good fit: Healthy infants and children aged 2 months (≥42 days) up to 5 years whose guardian can provide consent and vaccination records, and who have not previously received a pneumococcal vaccine, are ideal candidates.

Not a fit: Children who previously received any pneumococcal vaccine, have prior invasive pneumococcal disease, have a history of severe allergic reactions to vaccines or vaccine components, or (for infants under 12 months) were born prematurely or with low birth weight are excluded and unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, PCV24 could offer broader protection against more pneumococcal strains than current lower‑valent vaccines and reduce pneumococcal disease in young children.

How similar studies have performed: Licensed lower‑valent pneumococcal conjugate vaccines like the 13‑valent formulation have proven safety and effectiveness, and higher‑valent candidates have shown promising immunogenicity, but a 24‑valent PCV represents a newer approach with limited published pediatric Phase 2 data to date.

Eligibility criteria

Inclusion Criteria:

1. Healthy infants who are aged 2 months (42-89 days), 7-11 months, 12-23 months, and 2-5 years;
2. The participants' guardian provides a legal identity document and the participants' vaccination record;
3. The participant's 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. Severe congenital malformations or developmental disorders, genetic defects, or 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 platelet levels);
10. Have/have suffered from a serious neurological disorder (epilepsy or convulsions, but a 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. Receipt of immunoglobulins or other blood products within 3 months prior to administration of the investigational vaccine (except for hepatitis B immunoglobulin or rabies immunoglobulin used within 1 month), or planned use of such products during the study period;
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

Huanggang, Hubei and 2 other locations

• Qichun District Center for Disease Prevention and Control — Huanggang, Hubei, China (Recruiting)
• Xiangzhou District Center for Disease Prevention and Control — Xiangyang, Hubei, China (Recruiting)
• Xian'an District Center for Disease Prevention and Control — Xianning, Hubei, China (Recruiting)

Study contacts

• Study coordinator: Ye-qing Tong

Conditions Pneumococcal Infectious Disease; PCV24; Phase 2