Phase Ⅱ Clinical Trial of 24-valent Pneumococcal Polysaccharide Conjugate Vaccine

Evaluation of the Safety and Tolerability of 24-valent Pneumococcal Polysaccharide Conjugate Vaccine in Individuals Aged 18 Years and Above: A Random PhaseⅡClinical Trial.

In the treatment of pneumococcal diseases, the common use of penicillin-based antimicrobial agents has led to drug resistance, which has become a global challenge. Therefore, disease prevention through vaccination is essential. The 23-valent pneumococcal polysaccharide vaccine, the first widely used vaccine, has limitations. Subsequent pneumococcal polysaccharide conjugate vaccines have improved protection rates but increased cases of infections caused by non-vaccine serotype strains. Currently, vaccines available in China for pneumococcal disease prevention include the 23-valent polysaccharide vaccine (approved only for adults) and the 13-valent conjugate vaccine. PCV24 expands serotype coverage and converts capsular polysaccharides into T-cell-dependent antigens by binding them to proteins, stimulating humoral immunity and the complement system to generate specific antibodies and immunological memory for disease prevention. This study aims to preliminarily investigate the safety and immunogenicity of PCV24 vaccination in Chinese adults.

Study Overview

• Status: Completed
• Conditions: Streptococcus Pneumoniae Pneumonia
• Intervention / Treatment: Biological: low dose-1; Biological: low dose-2; Biological: high dose; Biological: positive control

Detailed Description

Streptococcus pneumoniae is a Gram-positive diplococcus, and its capsular polysaccharide is a key virulence factor. According to differences in the composition and structure of capsular polysaccharides, it can be divided into more than 90 serotypes, with varying viability and pathogenicity among different serotypes. As an important opportunistic pathogen, this bacterium can breach mucosal defense systems to cause invasive infections when host immunity declines, leading to diseases such as pneumonia, bacterial meningitis, bacteremia, sinusitis, and otitis media.

Antimicrobial agents commonly used in the treatment of pneumococcal diseases, such as penicillins, macrolides, and cephalosporins, have faced global challenges due to drug resistance, making vaccination essential for disease prevention. The World Health Organization (WHO) has classified pneumococcal diseases as a top priority for vaccination. The early widely used 23-valent pneumococcal polysaccharide vaccine had limitations, while subsequent 7-valent, 10-valent, and 13-valent pneumococcal polysaccharide conjugate vaccines improved protection rates but were associated with increased infections from non-vaccine serotype strains. Currently, only the 23-valent polysaccharide vaccine is approved for adult use in China. Pneumococcal conjugate vaccines convert capsular polysaccharides into T-cell-dependent antigens by binding them to proteins, thereby stimulating humoral immunity and the complement system to generate specific antibodies and immunological memory for disease prevention. This study aims to evaluate the safety and tolerability of a 24-valent pneumococcal polysaccharide conjugate vaccine in individuals aged 18 years and older.

• Study Type: Interventional
• Enrollment (Actual): 992
• Phase: Phase 2

Contacts and Locations

Study Locations

• China
  • Jiangsu
    • Nanjing, Jiangsu, China, 210000
      • Jiangsu Provincial Center for Diseases Control and Prevention

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 1.Age and Identification: Volunteers aged ≥18 years on the screening day, able to provide valid legal identification.

  2.Informed Consent: Volunteers who have received and understood the study information, voluntarily agreed to participate, and signed the Informed Consent Form.

  3.Compliance: Volunteers able and willing to adhere to the clinical trial protocol requirements and attend all scheduled visits.

Baseline Temperature: Axillary temperature ≤37.0°C on the enrollment day.

Exclusion Criteria:

• 5.Vaccination History: Prior receipt of pneumococcal conjugate vaccine; pneumococcal polysaccharide vaccine within the past 3 years; or a history of invasive Streptococcus pneumoniae disease.

  6.Severe Allergic Reactions: History of severe allergic reactions, such as anaphylactic shock, allergic laryngeal edema, allergic purpura, thrombocytopenic purpura, local allergic necrotic reaction (Arthus reaction), etc.

  7.Immunocompromised Status: Diagnosed congenital or acquired immunodeficiency; or receipt of systemic glucocorticoid therapy (e.g., prednisone or equivalent >5 mg/day for ≥2 consecutive weeks) within 1 month prior to vaccination (local, inhaled, or nebulized steroids are permitted).

  8.Severe Cardiovascular Diseases: History of arrhythmia, conduction block, myocardial infarction, or uncontrolled severe hypertension (on-site measurement: systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥100 mmHg).

  9.Acute Illness or Medication Use: Acute febrile illness, acute infectious disease, active cold symptoms, progressive influenza, or current use of related therapeutic medications.

  10.Neurological/Developmental Disorders: History of neurological impairment, severe congenital malformation, severe developmental disorder, severe genetic defect, or severe malnutrition.

  11.Neuropsychiatric History: Personal or family history of epilepsy, encephalopathy, or psychiatric disorders.

  12.Coagulation Abnormalities: Diagnosed thrombocytopenia, coagulation dysfunction (e.g., coagulation factor deficiency, coagulation disorders, platelet abnormalities), or contraindications to intramuscular injection (e.g., anticoagulant therapy).

  13.Splenic Abnormalities: Asplenia, functional asplenia, or splenectomy for any reason.

  14.Uncontrolled Chronic Diseases: Severe chronic diseases or progressive conditions that cannot be stably controlled.

  15.Blood Products/Immunoglobulins: Receipt of blood or blood products, or immunoglobulins within the past 3 months.

  16.Live Attenuated Vaccines: Vaccination with live attenuated vaccines within the past 14 days.

  17.Other Vaccines: Vaccination with other vaccines within the past 7 days. 18.Investigational Products: Receipt of other investigational drugs or vaccines within the past 1 month.

  19.Concurrent Studies: Current participation or planned participation in another clinical study of drugs or vaccines during the research period.

  20.Investigator's Discretion: Any other condition that, in the investigator's judgment, may interfere with study evaluation.

  21.Additional Exclusions for Specific Populations: Females of Childbearing Potential (18-49 years): Positive urine pregnancy test on enrollment day; lactation; or planning to become pregnant within 6 months.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PCV24 Low dose-1 group; Adults receive one dose of 0.5ml low dose-1 PCV24 vaccine，the low dose-1 group contained 4.0 μg of polysaccharides per vial for serotypes 3, 6B, and 12F, and 2.0 μg of polysaccharides per vial for the other 21 serotypes (1, 2, 4, 5, 6A, 7F, 8, 9N, 9V, 10A, 11A, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F). The polysaccharides of each serotype were bound to carrier proteins and adsorbed onto aluminum phosphate adjuvant (aluminum content: 0.125 mg/dose)	Biological: low dose-1; PCV24 (low-dose 1) developed by Shanghai Ruizhou Biotechnology Co., Ltd. and Changchun Ruizhou Biopharmaceutical Co., Ltd. is a liquid formulation. Each vial contains 0.5 ml, and the dosage is 0.5 ml per person per administration. The polysaccharide content of each serotype is as follows: 4.0 μg per vial for serotypes 3, 6B, and 12F; and 2.0 μg per vial for the other 21 serotypes, namely 1, 2, 4, 5, 6A, 7F, 8, 9N, 9V, 10A, 11A, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F. After binding to carrier proteins, the polysaccharides of each serotype are adsorbed on an aluminum phosphate adjuvant (aluminum content: 0.125 mg per dose).
Experimental: PCV24 Low dose-2 group; Adults receive one dose of 0.5ml low dose-2 PCV24 vaccine，the low dose-2 group is a liquid formulation of 0.5 ml per vial with a dosage of 0.5 ml per person per administration, containing 4.0 μg of polysaccharides per vial for serotypes 3, 6B and 12F and 2.0 μg per vial for each of the other 21 serotypes, with the polysaccharides of each serotype bound to carrier proteins and adsorbed on aluminum phosphate adjuvant (aluminum content: 0.25 mg per dose)	Biological: low dose-2; PCV24 (low-dose 2) developed by Shanghai Ruizhou Biotechnology Co., Ltd. and Changchun Ruizhou Biopharmaceutical Co., Ltd. is a liquid formulation. Each vial contains 0.5 ml, with a dosage of 0.5 ml per person per administration. The polysaccharide content of each serotype is as follows: 3 types (3, 6B, 12F): 4.0 μg per vial 21 other serotypes (1, 2, 4, 5, 6A, 7F, 8, 9N, 9V, 10A, 11A, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, 33F): 2.0 μg per vial After binding to carrier proteins, the polysaccharides of each serotype are adsorbed on an aluminum phosphate adjuvant with an aluminum content of 0.25 mg per dose.
Experimental: PCV24 High dose group; Adults receive one dose of 0.5ml High dose PCV24 vaccine， the high dose group is a liquid formulation of 0.5 ml per vial with a dosage of 0.5 ml per person per administration, containing 8.0 μg of polysaccharides per vial for serotypes 3, 6B and 12F and 4.0 μg per vial for each of the other 21 serotypes, with the polysaccharides of each serotype bound to carrier proteins and adsorbed on aluminum phosphate adjuvant (aluminum content: 0.25 mg per dose)	Biological: high dose; PCV24 (high-dose) developed by Shanghai Ruizhou Biotechnology Co., Ltd. and Changchun Ruizhou Biopharmaceutical Co., Ltd. is a liquid formulation. Each vial contains 0.5 ml, with a dosage of 0.5 ml per person per administration. The polysaccharide content of each serotype is as follows: 3 types (3, 6B, 12F): 8.0 μg per vial 21 other serotypes (1, 2, 4, 5, 6A, 7F, 8, 9N, 9V, 10A, 11A, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, 33F): 4.0 μg per vial After binding to carrier proteins, the polysaccharides of each serotype are adsorbed on an aluminum phosphate adjuvant with an aluminum content of 0.25 mg per dose.
Active Comparator: Positive control group; Adults receive one dose of 0.5ml PPV23 vaccine， the positive control is the PPV23 produced by Chengdu Institute of Biological Products, which is 0.5 ml per vial and 0.5 ml per dose per person and contains 25 μg of pneumococcal polysaccharides for each serotype of 1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F and 33F, as well as sodium chloride and water for injection.	Biological: positive control; PPV23 produced by Chengdu Institute of Biological Products is a formulation with each vial containing 0.5 ml, and the dosage is 0.5 ml per person per administration. It contains polysaccharides of the following pneumococcal serotypes: 1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15B, 17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F, with each serotype containing 25 μg of polysaccharide. In addition, it contains sodium chloride and water for injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate the immunogenicity after vaccination	The seroconversion rate of specific IgG antibodies against each serotype covered by the pneumococcal vaccine, detected by enzyme-linked immunosorbent assay (ELISA) at 30 days after immunization in each group.	Within 30 days after vaccination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate The incidence of adverse reactions after vaccination	The proportion of subjects reporting adverse reactions within 30 days after vaccination	within 30 days after vaccination
To evaluate The incidence of serious adverse events after vaccination	The proportion of subjects reporting serious adverse events within 6 months after vaccination	Within 6 months after vaccination

Collaborators and Investigators

• Sponsor: Jiangsu Province Centers for Disease Control and Prevention

Study record dates

Study Major Dates

• Study Start (Actual): April 20, 2024
• Primary Completion (Actual): November 30, 2024
• Study Completion (Actual): November 30, 2024

Study Registration Dates

• First Submitted: June 6, 2025
• First Submitted That Met QC Criteria: June 16, 2025
• First Posted (Actual): June 24, 2025

Study Record Updates

• Last Update Posted (Actual): June 24, 2025
• Last Update Submitted That Met QC Criteria: June 16, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Lung Diseases; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Streptococcal Infections; Pneumococcal Infections; Pneumonia, Bacterial; Pneumonia; Pneumonia, Pneumococcal
• Other Study ID Numbers: JSVCT183

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No