Clinical Trial of PCV24 in Adults Aged ≥18 Years

NCT07543198 | Completed Phase 1

• 1 other identifier: PRO-PCV24-1004
• Study Type: interventional
• Target: 385
• Locations: 1 country
• Sites: 1

Brief Summary

A Phase Ib/II clinical trial of 24-valent pneumococcal conjugate vaccine (PCV24)developed by Sinovac Life Science Co., Ltd will be conducted in adults aged ≥18 years. The objective of the study is to evaluate the safety and immunogenicity of Sinovac PCV24. The trial is a randomized, double-blind, Positive Controlled phase Ib/II clinical trial.

Conditions

Pneumococcal Infectious Disease

Outcome Measures

Primary Outcomes (5)

• Incidence of adverse reactions

  Incidence of adverse reactions of different doses of PCV24 in adults aged ≥18 years within 30 days after vaccination

  0-30 days after vaccination

• Pneumococcal serotype-specific opsonophagocytic assay (OPA) geometric mean titer (GMT) (phase II)

  OPA GMT 30 days after vaccination

  30 days after vaccination

• Proportion of pneumococcal serotype-specific OPA antibody titer increase≥4-fold(phase II)

  Proportion of OPA antibody titer increase≥four folds 30 days after vaccination

  30 days after vaccination

• Pneumococcal serotype-specific IgG antibody geometric mean concentration (GMC)(phase II)

  IgG GMC 30 days after vaccination

  30 days after vaccination

• Proportion of pneumococcal serotype-specific IgG antibody concentration increase≥4-fold(phase II)

  Proportion of IgG antibody concentration increase≥four folds 30 days after vaccination

  30 days after vaccination

Secondary Outcomes (5)

• Incidence of clinically significant abnormality in laboratory examination tests(phase Ib)

  0-3 days after vaccination

• Incidence of adverse reactions

  0-7 days after vaccination

• Incidence of serious adverse reactions(SAE)

  0-6 months after vaccination

• Pneumococcal serotype-specific OPA GMI(phase II)

  30 days after vaccination

• Pneumococcal serotype-specific IgG antibody geometric mean increase (GMI)(phase II)

  30 days after vaccination

Study Arms (7)

Low-dosage PCV24 (phase Ib)

EXPERIMENTAL

12 Participants aged 18-49years and 12 Participants aged ≥50years will receive Sinovac Low-dosage PCV24 . Route of administration is intramuscular injection at deltoid muscle of upper arm.Immunization schedule is 1 dose

Biological: Sinovac Low-dosage PCV24

Middle-dosage PCV24(phase Ib)

EXPERIMENTAL

12 Participants aged 18-49 years and 12 Participants aged ≥50years will receive Sinovac Middle-dosage PCV24 . Route of administration is intramuscular injection at deltoid muscle of upper arm.Immunization schedule is 1 dose

Biological: Sinovac Middle-dosage PCV24

High-dosage PCV24(phase Ib)

EXPERIMENTAL

12 Participants aged 18-49years will receive Sinovac High-dosage PCV24 . Route of administration is intramuscular injection at deltoid muscle of upper arm.Immunization schedule is 1 dose

Biological: Sinovac High-dosage PCV24

Pneumovax®(phase Ib)

ACTIVE COMPARATOR

12 Participants aged 18-49years and 6 Participants aged ≥50years will receive Pneumovax®(PPV23) . Route of administration is intramuscular injection at deltoid muscle of upper arm.Immunization schedule is 1 dose

Biological: Pneumovax®

Low-dosage PCV24(phase II)

EXPERIMENTAL

50 Participants aged 18-49years and 50 Participants aged ≥50years will receive Sinovac Low-dosage PCV24 . Route of administration is intramuscular injection at deltoid muscle of upper arm.Immunization schedule is 1 dose

Biological: Sinovac Low-dosage PCV24

Middle-dosage PCV24(phase II)

EXPERIMENTAL

50 Participants aged 18-49years and 50 Participants aged ≥50years will receive Sinovac Middle-dosage PCV24 . Route of administration is intramuscular injection at deltoid muscle of upper arm.Immunization schedule is 1 dose

Biological: Sinovac Middle-dosage PCV24

Pneumovax®(phase II)

ACTIVE COMPARATOR

50 Participants aged 18-49years and 50 Participants aged ≥50years will receive Pneumovax®(PPV23) . Route of administration is intramuscular injection at deltoid muscle of upper arm.Immunization schedule is 1 dose

Biological: Pneumovax®

Interventions

Sinovac Low-dosage PCV24 BIOLOGICAL

One dose of Sinovac Low-dosage PCV24 (0.5mL)

Low-dosage PCV24 (phase Ib); Low-dosage PCV24(phase II)

Sinovac Middle-dosage PCV24 BIOLOGICAL

One dose of Sinovac Middle-dosage PCV24(0.5mL)

Middle-dosage PCV24(phase II); Middle-dosage PCV24(phase Ib)

Sinovac High-dosage PCV24 BIOLOGICAL

One dose of Sinovac High-dosage PCV24(0.5mL)

High-dosage PCV24(phase Ib)

Pneumovax® BIOLOGICAL

One dose of PPV23 manufactured by MSD

Pneumovax®(phase II); Pneumovax®(phase Ib)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy adults aged ≥18 years, who can provide legal identification documents
• Fully understand and agree to sign the informed consent form
• Willing and able to follow all study procedures and stay in contact during the study

You may not qualify if:

• Received any pneumococcal vaccine;
• History of invasive pneumococcal diseases or other pneumococcal diseases caused by Streptococcus pneumoniae, as confirmed by laboratory tests;
• History of allergy or serious adverse reactions to the vaccine or vaccine components, or history of allergy, such as urticaria, dyspnea, angioedema and anaphylactic shock;
• Congenital malformations or developmental disorders, genetic defects, severe malnutrition;
• Have uncontrolled chronic diseases or history of severe diseases, including but not limited to cardiovascular diseases, metabolic diseases, hematological diseases,liver and kidney diseases, digestive diseases, respiratory diseases , malignant tumors and major functional organ transplantation history;
• Autoimmune diseases or immunodeficiency diseases (including but not limited to systemic lupus erythematosus, rheumatoid arthritis,autoimmune thyroid disease, asplenia, functional asplenia, HIV infection);
• Abnormalities in coagulation function (such as deficiency of coagulation factors, coagulation disorders, and abnormalities of platelets);
• Have/have suffered from a serious neurological disorder (epilepsy , convulsions or seizures) or mental illness or have a family history of such diseases;
• Long-term alcohol or drug abuse;
• Have received \> 14 days of immunosuppressive or other immunomodulatory therapy((such as prednisone ≥20 mg/day, or an equivalent dose)) in the past 6 months, or cytotoxic therapy, or plan to receive such therapy during the study period;
• Received immunoglobulin or other blood products within 3 months before receiving the l vaccine, or plan to receive such treatment during the study period;
• Received other investigational drugs or vaccines within 30 days before receiving the vaccine, or plan to receive such drugs or vaccines during the study;
• Received live attenuated vaccine within 14 days before receiving the vaccine;
• Received subunit or inactivated or other vaccine within 7 days before receiving the vaccine;
• Acute diseases or acute onset of chronic diseases within the past 7 days , or known or suspected active infection;

Sponsors & Collaborators

• Sinovac Life Sciences Co., Ltd.: lead

Study Sites (1)

Shaanxi Provincial Center for Disease Control and Prevention

Xi'an, Shaanxi, China

Location

MeSH Terms

Conditions

Pneumococcal Infections

Interventions

Pneumococcal Vaccines

Condition Hierarchy (Ancestors)

Streptococcal Infections; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Infections

Intervention Hierarchy (Ancestors)

Streptococcal Vaccines; Bacterial Vaccines; Vaccines; Biological Products; Complex Mixtures

Study Officials

• Weijun Hu

  Shaanxi Provincial Center for Disease Control and Prevention

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 14, 2026
• First Posted: April 21, 2026
• Study Start: June 18, 2025
• Primary Completion: February 26, 2026
• Study Completion: February 26, 2026
• Last Updated: April 21, 2026

Record last verified: 2026-04

Locations

CN (1)