Safety and Immunogenicity of the Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented and Adjuvanted) in Adults and Older Adults

April 1, 2026 updated by: Butantan Institute

Randomized, Double-Blind, Placebo-Controlled Phase I/II Clinical Trial To Evaluate The Safety And Immunogenicity Of The Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) From Instituto Butantan, In Adults And The Older Adults

This study aims to demonstrate the safety and immunogenicity of two formulations of the monovalent influenza vaccine candidate A (H5N8) (inactivated, fragmented, and adjuvanted with IB160) from the Instituto Butantan in adults and older adults, to be developed for situations of pandemic, epidemic or outbreak of avian type A/H5 in humans, in the context of pandemic preparedness.

Study Overview

Detailed Description

This is a clinical trial (randomized, double-blind, placebo-controlled Phase I/II) to evaluate the safety and immunogenicity of two formulations of the monovalent influenza vaccine candidate A (H5N8) (inactivated, fragmented, and adjuvanted with IB160) from the Instituto Butantan in adults and older adults. Safety will be assessed by the frequency (n, %) of participants with solicited (local and systemic) and unsolicited adverse events reported within 7 days post each vaccination; as well as the frequency of adverse reactions post causality evaluation. Immunogenicity will be assessed by seroprotection and seroconversion rates in the 21 days after the second dose.

Study Type

Interventional

Enrollment (Estimated)

700

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • São Paulo, Brazil, 05403-010
        • Not yet recruiting
        • Centro de Pesquisas Clínicas do Hospital das Clínicas da FMUSP
        • Contact:
    • Minas Gerais
      • Belo Horizonte, Minas Gerais, Brazil, 30750-140
        • Not yet recruiting
        • Centro de Terapias Avançadas E Inovadoras - Ct Terapias/Ufmg
        • Contact:
    • Pernambuco
      • Recife, Pernambuco, Brazil, 52011-040
        • Recruiting
        • Platano Centro De Pesquisa Clinica LTDA
        • Contact:
    • São Paulo
      • Serrana, São Paulo, Brazil
        • Not yet recruiting
        • Fundação de Apoio ao Ensino, Pesquisa e Assistência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preta da Universidade de São Paulo - (Centro de Pesquisa Clínica - S)
        • Contact:
      • São José do Rio Preto, São Paulo, Brazil, 15090-000
        • Not yet recruiting
        • Fundação Faculdade Regional de Medicina de São Jose do Rio Preto - (Centro integrado de Pesquisa CIP)
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Males and non-pregnant females aged ≥ 18 years at the time of the first study vaccination.
  2. Be in good health and clinically stable (defined as having no pre-existing health condition or having a pre-existing health condition that has not required a change in treatment or hospitalization for worsening of disease in the 3 months prior to the date of the first study vaccination).
  3. Agree to participate in the study and provide written informed consent prior to the initiation of any study procedures.
  4. Be able and willing to comply with all study procedures, including completing Participant Diaries, collecting blood samples, and being available for scheduled study visits and contacts.
  5. For females of childbearing potential, have a negative pregnancy test prior to the first study vaccination.
  6. For women of childbearing potential, be willing to use effective contraceptive measures during the screening visit until at least 30 days after the second study vaccination.

Exclusion Criteria:

  1. Having received any vaccine (including seasonal influenza) 28 days prior to the date of the first study vaccination or having any vaccination in the period from the first vaccination to the immune response assessment visit after the last vaccination.
  2. Known hypersensitivity or allergy to eggs, chicken proteins, squalene-based adjuvants, or any other component of the investigational product.
  3. History of serious adverse reaction or anaphylaxis to any previous influenza vaccine (licensed or not).
  4. Having received any influenza A/H5 vaccine or history of exposure to avian influenza A/H5.
  5. Presence of a bleeding disorder or any condition that contraindicates intramuscular injection.
  6. Having received immunoglobulin, blood, or any blood-derived product in the 3 months prior to the date of the first study vaccination or having had immunoglobulin or blood-derived product administered during the entire follow-up of the study.
  7. Having received a solid organ, bone marrow, or stem cell transplant.
  8. Having a history of asplenia (anatomic or functional).
  9. Having any confirmed or suspected immunosuppressive or immunodeficiency condition, including a history of human immunodeficiency virus (HIV) infection.
  10. Having a history of Guillain-Barré syndrome or other demyelinating disease.
  11. Having a history of neurological disease, seizures, or progressive or severe neurological disorder.
  12. History of malignant neoplasm or previous history of malignant neoplasm being disease-free for 5 years at the date of the first study vaccination (with the exception of basal cell carcinoma of the skin), autoimmune disease (including type 1 diabetes mellitus), liver cirrhosis and renal failure.
  13. History of significant, progressive or decompensated chronic disease in the 3 months prior to the date of the first study vaccination (complicated type 2 diabetes mellitus, liver disease, kidney disease, heart disease, advanced arteriosclerotic disease or lung disease such as oxygen-dependent chronic obstructive pulmonary disease, among others).
  14. Having received or using radiotherapy, chemotherapy, cytotoxic drugs, immunosuppressants or immunomodulators in the 6 months prior to the date of the first study vaccination.
  15. Use of systemic corticosteroids (oral or parenteral) in the 3 months prior to the date of the first study vaccination, at an immunosuppressive dose equivalent to a dose of ≥ 20 mg of prednisone per day for ≥ 14 days or a cumulative dose of ≥ 280 mg. Topical use of corticosteroids (e.g., cream, eye drops, inhalation and intranasal sprays) is permitted, within the dosage indicated on the product label.
  16. Presenting a behavioral, cognitive disorder/disorder or psychiatric illness that, in the opinion of the Investigator, may interfere with the ability to participate in the study.
  17. Infection with the human immunodeficiency virus (HIV), hepatitis B or hepatitis C.
  18. Abuse of alcohol or drugs in the 12 months prior to the date of the first study vaccination, that may interfere with the ability to participate in the study.
  19. Body mass index (BMI) ≥ 35 kg/m2 on the date of the first study vaccination.
  20. Clinically significant abnormalities in the general physical examination.
  21. Major surgery or surgery with the use of general anaesthesia planned to occur in the period from the first vaccination to the visit to assess the immune response after the last vaccination.
  22. Women who are pregnant, breastfeeding or planning to become pregnant during the 30 days after the last vaccination in the study.
  23. Laboratory parameter values at the screening visit equal to or greater than grade 2 will be considered as a criterion for exclusion from participation in the study.
  24. Presenting any clinically significant condition or situation that, in the opinion of the Investigator, represents a risk to the participant health or may interfere with the evaluation of the study objectives, the schedule of visits, participation in or completion of the study (such as planned travel or change of residence, among others).
  25. Having participated in another clinical trial involving an experimental product, with less than three months between the completion of that follow-up and the planned date of the first vaccination in this study, or plans to enter a clinical study during the period of this study.
  26. Institutionalized individual (people residing in long-term care, assistance or health care institutions and deprived of liberty).

aa. Being related to or part of the research centre staff or employee directly involved in the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Monovalent Influenza Vaccine A (H5N8) 7.5 mcg
Intervention: Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) from Instituto Butantan, containing 7.5 mcg/dose of hemagglutinin (HA) and adjuvant IB160 (0.5 mL/dose of final combined product).
Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) 7.5 mcg + IB160 adjuvant (0.5mL total)
Other Names:
  • Avian Flu vaccine
Experimental: Monovalent influenza vaccine A (H5N8) 15 mcg
Intervention: Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) from Instituto Butantan, containing 15 mcg/dose of hemagglutinin (HA) and adjuvant IB160 (0.5 mL/dose of final combined product).
Monovalent influenza vaccine type A (H5N8) 15 mcg + IB160 adjuvant (0.5mL total)
Other Names:
  • Avian Flu vaccine
Placebo Comparator: Placebo
Phosphate buffered saline (PBS) (0.5 mL/dose).
Phosphate buffered saline (PBS) (0.5 mL/dose).
Other Names:
  • Control arm

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Safety - Percentage of participants with solicited and unsolicited adverse events
Time Frame: 7 days post each vaccination.
Percentage (%) of participants with solicited (local and systemic) and unsolicited adverse events, for each intervention group, in adults and older adults.
7 days post each vaccination.
Safety - Percentage of solicited and unsolicited adverse events by intensity degree
Time Frame: 7 days post each vaccination
Percentage of solicited and unsolicited adverse events by intensity degree for each intervention group, in adults and older adults.
7 days post each vaccination
Safety - Percentage of participants with solicited and unsolicited adverse reactions
Time Frame: 7 days post each vaccination
Percentage of participants with solicited and unsolicited adverse reactions, for each intervention group, in adults and older adults.
7 days post each vaccination
Safety - Percentage of solicited and unsolicited adverse reactions by intensity degree
Time Frame: 7 days post each vaccination
Percentage of solicited and unsolicited adverse reactions by intensity degree for each intervention group, in adults and older adults.
7 days post each vaccination
Safety - Description of solicited adverse reactions, regarding duration, time until onset and use of medication
Time Frame: 7 days post each vaccination
Description of solicited adverse reactions, regarding duration, time until onset and use of medication, for each intervention group, in adults and older adults.
7 days post each vaccination
Immunogenicity - Seroconversion rate post second vaccination
Time Frame: 21 days post second vaccination
Seroconversion rate after the second vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
21 days post second vaccination
Immunogenicity - Seroprotection rate post second vaccination
Time Frame: 21 days post second vaccination
Seroprotection rate after the second vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
21 days post second vaccination

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Safety - Percentage of participants with unsolicited adverse events
Time Frame: 21 days post each vaccination
Percentage of participants with unsolicited adverse events, for each intervention group, in adults and older adults.
21 days post each vaccination
Safety - Percentage and intensity of unsolicited adverse events
Time Frame: 21 days post each vaccination
Percentage and intensity of unsolicited adverse events, for each intervention group, in adults and older adults.
21 days post each vaccination
Safety - Percentage of participants with unsolicited adverse reactions
Time Frame: 21 days post each vaccination
Percentage of participants with unsolicited adverse reactions, for each intervention group, in adults and older adults.
21 days post each vaccination
Safety - Percentage and intensity of unsolicited adverse reactions
Time Frame: 21 days post second vaccination
Percentage and intensity of unsolicited adverse reactions,, for each intervention group, in adults and older adults.
21 days post second vaccination
Percentage of participants with adverse events of special interest (AEI)
Time Frame: the entire follow-up of the study (6 months)
Percentage of participants with adverse events of special interest (AEI), for each intervention group, in adults and older adults.
the entire follow-up of the study (6 months)
Safety - Percentage and intensity of the participants with adverse events of special interest (AEI)
Time Frame: The entire follow-up of the study (6 months)
Percentage and intensity of the participants with adverse events of special interest (AEI), for each intervention group, in adults and older adults.
The entire follow-up of the study (6 months)
Safety - Percentage of participants with serious adverse events (SAE)
Time Frame: Entire follow-up of the study (6 months)
Percentage of participants with serious adverse events (SAE), for each intervention group, in adults and older adults.
Entire follow-up of the study (6 months)
Safety - Percentage and intensity of serious adverse events (SAE)
Time Frame: entire follow-up of the study (6 months)
Percentage and intensity of serious adverse events (SAE), for each intervention group, in adults and older adults.
entire follow-up of the study (6 months)
Immunogenicity - Ratio between the Geometric Mean Titers (rGMT) of antibodies
Time Frame: 21 days post the first vaccination
Ratio between the Geometric Mean Titers (rGMT) of antibodies compared to that of pre-vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
21 days post the first vaccination
Immunogenicity - Ratio between the Geometric Mean Titers (rGMT) of antibodies
Time Frame: 21 days post the second vaccination
Ratio of the Geometric Mean Titers (rGMT) of antibodies, post second vaccination about that of pre-vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
21 days post the second vaccination
Immunogenicity - Seroconversion rate
Time Frame: 21 days post the first vaccination
Seroconversion rate (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
21 days post the first vaccination
Immunogenicity - Geometric Mean Titers (GMT)
Time Frame: pre-vaccination, 21 days post the first vaccination and 21 days post the second vaccination.
Geometric Mean Titers (GMT) pre and post-vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
pre-vaccination, 21 days post the first vaccination and 21 days post the second vaccination.
Immunogenicity - Seroprotection rate
Time Frame: pre-vaccination and 21 days post first vaccination
Seroprotection rate pre and post-vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
pre-vaccination and 21 days post first vaccination
Immunogenicity - Ratio between the Geometric Mean Titers (rGMT) of antibodies
Time Frame: 21 days post the first vaccination
Ratio between the Geometric Mean Titers (rGMT) of antibodies, pre and post-vaccination (by microneutralization test - MN), for each intervention group, in adults and older adults.
21 days post the first vaccination
Immunogenicity - Ratio between the Geometric Mean Titers (rGMT) of antibodies
Time Frame: 21 days post the second vaccination
Ratio between the Geometric Mean Titers (rGMT) of antibodies, pre and post-vaccination (by microneutralization test - MN), for each intervention group, in adults and older adults.
21 days post the second vaccination
Immunogenicity - Seroconversion rate pre and post vaccination
Time Frame: 21 days post the first vaccination and 21 days post the second vaccination.
Seroconversion rate 21 days post the first vaccination and 21 days post the second vaccination (by microneutralization test - MN), for each intervention group, in adults and older adults.
21 days post the first vaccination and 21 days post the second vaccination.
Immunogenicity - Seroprotection rate pre and post-vaccination
Time Frame: pre-vaccination, 21 days post the first vaccination and 21 days post the second vaccination
Seroprotection rate pre-vaccination, 21 days after the first vaccination and 21 days after the second vaccination (by microneutralization test - MN), for each intervention group, in adults and older adults.
pre-vaccination, 21 days post the first vaccination and 21 days post the second vaccination
Immunogenicity - Geometric Mean Titers (GMT) pre and post-vaccination
Time Frame: pre vaccination, 21 days post the first vaccination and 21 days post the second vaccination.
Geometric Mean Titers (GMT) pre vaccination, 21 days post the first vaccination and 21 days after the second vaccination (by the microneutralization test - MN), for each intervention group, in adults and older adults.
pre vaccination, 21 days post the first vaccination and 21 days post the second vaccination.
Immunogenicity - Estimation of rGMT between the Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) containing 7.5 mcg of HA/dose compared to that containing 15 mcg of HA/dose
Time Frame: 21 days post the second vaccination
Estimation of rGMT between the Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) containing 7.5 mcg of HA/dose compared to that containing 15 mcg of HA/dose (by the hemagglutination inhibition test - HI)
21 days post the second vaccination

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 10, 2025

Primary Completion (Estimated)

August 10, 2027

Study Completion (Estimated)

October 10, 2027

Study Registration Dates

First Submitted

February 14, 2025

First Submitted That Met QC Criteria

February 19, 2025

First Posted (Actual)

February 24, 2025

Study Record Updates

Last Update Posted (Actual)

April 2, 2026

Last Update Submitted That Met QC Criteria

April 1, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

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

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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