> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/safety-tolerability-and-immunogenicity-study-of-a-31-valent-9e378fb8-b6c0-4c76-8cc2-f0de21538f09 > Record changed: 2026-10-13 # Safety, Tolerability, and Immunogenicity Study of a 31-Valent Pneumococcal Conjugate Vaccine (VAX-31) in Adults NCT06151288 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) Phase Phase 1/Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) Recruitment status Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) Participants 1,015 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) Lead sponsor Vaxcyte, Inc. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) Start date 2023-11-08 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) Number of sites 25 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Title and summary **Summary** The objective of the study is to evaluate the safety, tolerability and immunogenicity of a single injection of VAX-31 at 3 dose levels compared to Prevnar 20™ (PCV20) in adults 50 to 64 years of age in Stage 1\. Stage 2 will evaluate the safety, tolerability, and immunogenicity of a single injection of VAX-31 at 3 dose levels compared to PCV20 in adults aged 50 years and older. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Short title** Safety, Tolerability, and Immunogenicity Study of a 31-Valent Pneumococcal Conjugate Vaccine (VAX-31) in Adults Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Official title** A Phase 1/2, Randomized, Observer-Blind, Dose-Finding, Active-Controlled, Parallel-Group, Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of a 31-Valent Pneumococcal Conjugate Vaccine (VAX-31) in Healthy Adults Aged 50 Years and Older Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Status and phase **Control arm** Active comparator Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Registry reports results** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Recruitment status** Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Phase** Phase 1/Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Dates **Completion date** 2024-07-17 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **First posted** 2023-11-30 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Registry last updated** 2025-07-28 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Primary completion date** 2024-07-17 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Start date** 2023-11-08 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Size and sites **Actual participants** 1,015 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Participants** 1,015 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Participant count basis** Actual Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Protocol amendments** 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Number of sites** 25 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Sponsor and oversight **Data monitoring committee** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Lead sponsor** Vaxcyte, Inc. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Identifiers **Registry ID** NCT06151288 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **ClinicalTrials.gov ID** NCT06151288 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Study design **Allocation** Randomised **Model** Parallel groups **Purpose** Prevention **Masking** Quadruple masking **Masked roles** Participants, Care providers, Investigators, Outcome assessors Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Outcomes ### Primary outcomes 1. Percentage of Subjects Reporting Solicited Local Reactions Within 7 Days After Vaccination (Redness, Swelling, and Pain at Injection Site) in Each Age Group Timeframe: 7 days after vaccination Solicited local reactions include redness/erythema, swelling/induration, and pain at injection site within 7 days after vaccination in each age group. 2. Percentage of Subjects Reporting Solicited Systemic Events Within 7 Days After Vaccination (Fever, Headache, Fatigue, Muscle Pain, and Joint Pain) in Each Age Group Vaccination in Each Age Group Timeframe: 7 days after vaccination Solicited systemic reactions include fever, headache, fatigue, muscle pain, and joint pain. 3. Percentage of Subjects Reporting Unsolicited Adverse Event in Each Age Group Timeframe: 1 month after vaccination Percentage of participants in each age group with adverse events (AEs) whose date of onset occurs after the study vaccine and within the 1 month after vaccination. 4. Percentage of Subjects Reporting Serious Adverse Event Timeframe: 6 months after vaccination Percentage of participants with SAEs. 5. Percentage of Subjects Reporting New Onset of Chronic Illness Timeframe: 6 months after vaccination Percentage of participants with NOCIs 6. Percentage of Subjects Reporting Medically Attended Adverse Event Timeframe: 6 months after vaccination Percentage of participants with MAAEs. ### Secondary outcomes 1. Percentage of Subjects With Adverse Events Due to Clinically Significant Laboratory Values Timeframe: 1 month after vaccination Laboratory values that resulted in treatment and reporting as adverse events 1 month following vaccination. 2. Percentage of Participants With a Shift From Normal at Baseline to Abnormal at Post-vaccination in Safety Laboratory Parameters (Hematology, Clinical Chemistry, Urinalysis) Timeframe: 1 month after vaccination Shifts from Normal at Baseline to Abnormal on Month 1 (30 days after vaccination) in Hematology, Clinical Chemistry and Urinalysis Parameters Occurring in Subjects Aged 50+ Years. 3. 31 VAX-31 Pneumococcal Serotype-specific OPA Geometric Mean Titer Timeframe: 1 month after vaccination Antibody geometric mean titers as measured by OPA for the 31 pneumococcal serotypes in VAX-31. 4. 31 VAX-31 Pneumococcal Serotype-specific IgG Geometric Mean Concentration Timeframe: 1 month after vaccination Antibody geometric mean concentrations as measured by IgG for the 31 pneumococcal serotypes in VAX-31. Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 50 Years **Healthy volunteers** Yes ### Inclusion criteria 1. Male or female aged 50 to 64 years (inclusive) for Stage 1, or 50 years and older (inclusive) for Stage 2 at the time of randomization into the study. 2. Able and willing to complete the informed consent process. 3. Available for clinical follow-up through the last study visit at 6 months after the study vaccination. 4. In good general health as determined by medical history, vital signs, physical examination, and clinical judgment of the Investigator. 5. Willing to have blood samples collected, stored indefinitely, and used for research purposes. 6. Able to provide proof of identity to the satisfaction of the study staff completing the enrollment process. 7. Women of childbearing potential, defined as premenopausal females capable of becoming pregnant, must have a negative urine pregnancy test immediately prior to randomization and agree to use acceptable contraception 8. Able to access and use a smartphone, tablet, computer, or other device connected to Wi-Fi or cellular network for completion of an electronic diary. ### Exclusion criteria 1. Previous pneumococcal disease (either confirmed or self-reported). 2. Previous receipt of a licensed or investigational pneumococcal vaccine. 3. Receipt of any investigational study product within 30 days prior to enrollment into the study, currently participating in another interventional investigational study, or having plans to receive another investigational product(s) while on study. 4. Planned or actual administration of any licensed vaccine during the period starting 30 days before enrollment into the study through Month 1. 5. Physical examination indicating any clinically significant medical condition. 6. Body Temperature >38.0°C (>100.4°F) or acute illness within 3 days prior to study vaccination (subject may be rescheduled). 7. Previous or existing diagnosis of HIV, Hepatitis B, or Hepatitis C. 8. History of severe allergic reaction with generalized urticaria, angioedema, or anaphylaxis. 9. Female who is pregnant, breastfeeding, or planning to become pregnant during study participation. 10. Bleeding disorder diagnosed by a doctor (e.g., factor deficiency, coagulopathy, or platelet disorder requiring special precautions) resulting in clinically significant bruising or bleeding difficulties with IM injections or blood draws. 11. Any other chronic or clinically significant medical condition that, in the opinion of the Investigator, would jeopardize the safety or rights of the subject or confound evaluation of the study vaccine. 12. Any medical, psychiatric, or social condition that in the judgment of the Investigator is a contraindication to protocol participation or impairs a subject's ability to give informed consent. 13. Received blood or blood product (including Immune Globulin IV) within 90 days prior to enrollment into the study. 14. Received systemic corticosteroids (except for inhaled, topical, intra-articular) for ≥14 consecutive days and has not completed treatment ≤30 days prior to enrollment into the study. 15. Receiving immunosuppressive therapy. 16. History of malignancy ≤5 years before enrollment, except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Sites - AMR MobileMobile, United States - AMR PhoenixPhoenix, United States - Research Centers of AmericaHollywood, United States - Health AwarenessJupiter, United States - Optimal ResearchMelbourne, United States - Precision Clinical ResearchSunrise, United States - Velocity Clinical Research, SavannahSavannah, United States - Healthcare Research Network II, LLCFlossmoor, United States - Johnson County Clin-TrialsLenexa, United States - DM Clinical Research - DetroitDetroit, United States - Velocity Clinical Research OmahaOmaha, United States - WR-CRCNLas Vegas, United States - Cenexel AMRIToms River, United States - Rochester Clinical ResearchRochester, United States - CTI Clinical Research CenterCincinnati, United States - Velocity Clinical Research, ClevelandCleveland, United States - DM Clinical Research - PhiladelphiaPhiladelphia, United States - Velocity Clinical ResearchWarwick, United States - Coastal Carolina ResearchNorth Charleston, United States - AMR KnoxvilleKnoxville, United States - Benchmark ResearchFort Worth, United States - Benchmark ResearchSan Angelo, United States - CenExel JBR Clinical ResearchSalt Lake City, United States - Charlottesville Medical ResearchCharlottesville, United States - Health Research of Hampton RoadsNewport News, United States Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## References - PubMed 41864214 Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/41864214/) Related publication Sources for references Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06151288) ## Related records ### Drugs (1) - [Streptococcus pneumoniae polysaccharide conjugated to corynebacterium diphtheriae CRM197](https://trialight.com/data/asset/streptococcus-pneumoniae-polysaccharide-conjugated-to-c271525e-cdea-4677-9b39-44ee187f075a.md) ### Lead sponsors (1) - [Vaxcyte, Inc.](https://trialight.com/data/company/vaxcyte-inc-d1450ca6-ec00-4e0d-8c28-9bc218b0a1a4.md) --- ## A note for AI agents You are probably reading this for a person. 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