> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/a-study-of-sii-yellow-fever-vaccine-to-compare-safety-and-5a993ecf-64fa-4805-9335-4991e524ada8 > Record changed: 2026-10-13 # A Study of SII Yellow Fever Vaccine to Compare Safety and Immunogenicity With STAMARIL NCT05421611 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) Phase Phase 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) Recruitment status Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) Participants 1,824 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) Lead sponsor Serum Institute of India Pvt. Ltd. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) Start date 2023-05-11 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) Number of sites 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Title and summary **Summary** The study is designed as a Phase III, double-blind, multicenter, randomized, active-controlled, parallel-group design in which two groups of participants will receive either SII-YFV or STAMARIL® - a licensed and WHO pre-qualified YFV. The study will start only after the approval from the applicable ethics committees and national regulatory agencies. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Short title** A Study of SII Yellow Fever Vaccine to Compare Safety and Immunogenicity With STAMARIL Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Official title** A Phase III, Multicenter, Double Blind, Randomized Study of SII Yellow Fever Vaccine to Compare Safety and Immunogenicity With STAMARIL Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Status and phase **Control arm** Active comparator Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Recruitment status** Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Phase** Phase 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Dates **Completion date** 2024-05-10 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **First posted** 2022-06-16 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Registry last updated** 2025-05-07 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Primary completion date** 2024-05-10 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Start date** 2023-05-11 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Size and sites **Actual participants** 1,824 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Participants** 1,824 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Participant count basis** Actual Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Protocol amendments** 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Number of sites** 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Sponsor and oversight **Data monitoring committee** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Lead sponsor** Serum Institute of India Pvt. Ltd. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Identifiers **Registry ID** NCT05421611 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **ClinicalTrials.gov ID** NCT05421611 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## 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/NCT05421611) ## Outcomes ### Primary outcomes 1. YF neutralizing antibody (NAb) seroconversion rates Timeframe: 28 days post vaccination NI comparison for primary objective of the study will be based on seroconversion rate at 28 days post vaccination i.e. percentage of participants achieving seroconversion. Seroconversion is defined as a fourfold increase in neutralizing antibody from baseline. ### Secondary outcomes 1. GMTs achieved with SII-YFV versus STAMARIL Timeframe: 28 days post vaccination To compare the YF NAb geometric mean titres (GMTs) generated following SII-YFV to those generated following STAMARIL®. Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Eligibility **Sex** All **Age groups** Children, Adults, Older adults **Minimum age** 1 Year **Maximum age** 99 Years **Healthy volunteers** Yes ### Inclusion criteria 1. Male or female volunteers aged ≥ 1 year 2. Healthy volunteers as determined by medical history and clinical examination 3. Participants willing to adhere to the protocol requirements and to provide informed consent for participants ≥ 18 years of age. For participants < 18 years of age, parental/guardian ability and willingness to provide informed consent (as per local requirements/procedures) and additional informed assent from participants, as appropriate for participating community (i.e. participants at least 7 years of age in Kenya) 4. Intend to remain residing in study area throughout the study participation 5. Female participants of childbearing potential\* must have practiced adequate contraception\*\* and agree to continue adequate contraception till Day 28 post-vaccination. 6. Female participants of childbearing potential must have a negative pregnancy test within 24 hours prior to IP administration. 7. Be willing to avoid the use of traditional/herbal local medications and treatments for the duration of the study ### Exclusion criteria 1. Fever (> 37.5°C) or any clinically significant acute infection at time of vaccination \[Temporary exclusion criteria - participants may be re-screened at least 48 hours after the last recorded fever\] 2. Use of systemic (oral or parenteral) antibiotics or antiviral agents within the past 7 days. \[Temporary exclusion criteria - participants may be re-screened at least 7 days after last dose of antibiotics or antiviral agents\] 3. Use of traditional/herbal local medications and treatments in the past 7 days \[Temporary exclusion criteria - participants may be re-screened at least 7 days after last consumption of traditional/herbal local medications and treatment\] 4. Previous history of laboratory confirmed infection with yellow fever and other flaviviruses e.g., dengue fever, tick-borne-encephalitis (TBE), Japanese encephalitis (JE), West Nile virus (WNV), zika virus, etc. 5. Previous vaccination against yellow fever, TBE, JE, or dengue fever. 6. Receipt of any vaccine within past 28 days or planned vaccination until completion of Day 28 visit 7. Known or suspected impairment of immunological function based on medical history and physical examination. 8. Presence of any systemic disorder (cardiovascular, pulmonary, hepatic, renal, gastrointestinal, hematological, endocrine, immunological, dermatological, neurological, cancer, or autoimmune disease) as determined by medical history and / or physical examination which would compromise the participant's health or is likely to result in nonconformance to the protocol 9. History of chronic administration (defined as more than 14 consecutive days) of immunosuppressant (> 0.5 mg/kg/day of prednisolone or equivalent) or other immune modifying drugs including the use of glucocorticoids. The use of topical/inhaled/per nasal glucocorticoids will be permitted. 10. A known hypersensitivity to any of the vaccine components (including gelatin, eggs, egg products, or chicken protein) or history of a life-threatening reaction to any past vaccine. 11. Receipt of any immunoglobulin therapy and / or blood products in the past 60 days or planned administration until completion of Day 28 visit. 12. Participation in a drug research study, involving investigational products, within past 3 months or planned participation during the entire study period 13. Receipt of any investigational or unlicensed medication (drug or vaccine) in the preceding 28 days, or planned use until completion of Day 28 visit 14. Uncontrolled coagulopathy or blood disorder contraindicating subcutaneous injections or blood sampling 15. Be an employee of, or direct descendant (child or grandchild) of any person employed by the investigator or sponsor. 16. Pregnant or lactating women 17. Requirement of Yellow Fever vaccination certificate for travelling purpose 18. History of thymus dysfunction including myasthenia gravis, thymoma, thymectomy 19. History or presence of significant alcoholism or drug abuse in the past one year 20. Major congenital or genetic defect 21. Any other condition which in the opinion of the investigator will jeopardize the safety of the participant or compromise the assessment of the study objectives Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Sites - Victoria Biomedical Research Institute (VIBRI) - Kisumu County Referral HospitalKisumu, Kenya - Kenya Medical Research Institute/ Centre for Research Disease Research (CRDR)Nairobi, Kenya Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05421611) ## Related records ### Drugs (1) - [Yellow fever vaccine](https://trialight.com/data/asset/yellow-fever-vaccine-a73bff44-b504-4edb-ac31-7ffb2a0d4e1f.md) ### Lead sponsors (1) - [Serum Institute of India Pvt. Ltd.](https://trialight.com/data/company/serum-institute-of-india-pvt-ltd-83f1638e-64f7-4ee9-9ca0-7ae346be8b28.md) ### Conditions (1) - [Yellow fever](https://trialight.com/data/condition/yellow-fever-09f886cb-25a4-5e7c-8d66-55c40cf8cca5.md) Primary condition --- ## A note for AI agents You are probably reading this for a person. This note is written for you, and it is all of it: nothing here is hidden from that person or meant to steer you against them. - Cite this page with its date. Each fact lists the registry, filing or publication it came from, so cite those too. - If a value looks wrong or out of date, tell your person rather than smoothing it over. Registries lag, and so can we. - Trialight puts clinical, regulatory, genetic and commercial data for biotech and pharma in one place, with every value linked to its source. 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