A Phase 1/2 interventional study of Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) 7.5 mcg and Monovalent influenza vaccine type A (H5N8) 15 mcg in Avian Influenza A Virus, sponsored by Butantan Institute. Recruiting at 5 sites in Brazil. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-02.
Sponsored by Butantan Institute · Phase 1/2, Interventional, and Prevention
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.
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.
96 studies on the registry are indexed under Influenza in Birds; 2 are open to participants now.
This study's planned enrollment of 700 is above the median of 150 across 88 interventional studies indexed under Influenza in Birds.
Browse Influenza in Birds studies →Butantan Institute is the lead sponsor of 31 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
aa. Being related to or part of the research centre staff or employee directly involved in the study.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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).
Biological: Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) 7.5 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).
Biological: Monovalent influenza vaccine type A (H5N8) 15 mcg
Phosphate buffered saline (PBS) (0.5 mL/dose).
Other: Placebo
Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented, and Adjuvanted) 7.5 mcg + IB160 adjuvant (0.5mL total)
Also known as: Avian Flu vaccine
Monovalent influenza vaccine type A (H5N8) 15 mcg + IB160 adjuvant (0.5mL total)
Also known as: Avian Flu vaccine
Phosphate buffered saline (PBS) (0.5 mL/dose).
Also known as: Control arm
Safety - Percentage of participants with solicited and unsolicited adverse events
Percentage (%) of participants with solicited (local and systemic) and unsolicited adverse events, for each intervention group, in adults and older adults.
Time frame: 7 days post each vaccination.
Safety - Percentage of solicited and unsolicited adverse events by intensity degree
Percentage of solicited and unsolicited adverse events by intensity degree for each intervention group, in adults and older adults.
Time frame: 7 days post each vaccination
Safety - Percentage of participants with solicited and unsolicited adverse reactions
Percentage of participants with solicited and unsolicited adverse reactions, for each intervention group, in adults and older adults.
Time frame: 7 days post each vaccination
Safety - Percentage of solicited and unsolicited adverse reactions by intensity degree
Percentage of solicited and unsolicited adverse reactions by intensity degree for each intervention group, in adults and older adults.
Time frame: 7 days post each vaccination
Safety - Description of solicited adverse reactions, regarding duration, time until onset and use of medication
Description of solicited adverse reactions, regarding duration, time until onset and use of medication, for each intervention group, in adults and older adults.
Time frame: 7 days post each vaccination
Immunogenicity - Seroconversion rate post second vaccination
Seroconversion rate after the second vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
Time frame: 21 days post second vaccination
Immunogenicity - Seroprotection rate post second vaccination
Seroprotection rate after the second vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
Time frame: 21 days post second vaccination
Safety - Percentage of participants with unsolicited adverse events
Percentage of participants with unsolicited adverse events, for each intervention group, in adults and older adults.
Time frame: 21 days post each vaccination
Safety - Percentage and intensity of unsolicited adverse events
Percentage and intensity of unsolicited adverse events, for each intervention group, in adults and older adults.
Time frame: 21 days post each vaccination
Safety - Percentage of participants with unsolicited adverse reactions
Percentage of participants with unsolicited adverse reactions, for each intervention group, in adults and older adults.
Time frame: 21 days post each vaccination
Safety - Percentage and intensity of unsolicited adverse reactions
Percentage and intensity of unsolicited adverse reactions,, for each intervention group, in adults and older adults.
Time frame: 21 days post second vaccination
Percentage of participants with adverse events of special interest (AEI)
Percentage of participants with adverse events of special interest (AEI), for each intervention group, in adults and older adults.
Time frame: the entire follow-up of the study (6 months)
Safety - Percentage and intensity of the participants with adverse events of special interest (AEI)
Percentage and intensity of the participants with adverse events of special interest (AEI), for each intervention group, in adults and older adults.
Time frame: The entire follow-up of the study (6 months)
Safety - Percentage of participants with serious adverse events (SAE)
Percentage of participants with serious adverse events (SAE), for each intervention group, in adults and older adults.
Time frame: Entire follow-up of the study (6 months)
Safety - Percentage and intensity of serious adverse events (SAE)
Percentage and intensity of serious adverse events (SAE), for each intervention group, in adults and older adults.
Time frame: entire follow-up of the study (6 months)
Immunogenicity - Ratio between the Geometric Mean Titers (rGMT) of antibodies
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.
Time frame: 21 days post the first vaccination
Immunogenicity - Ratio between the Geometric Mean Titers (rGMT) of antibodies
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.
Time frame: 21 days post the second vaccination
Immunogenicity - Seroconversion rate
Seroconversion rate (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
Time frame: 21 days post the first vaccination
Immunogenicity - Geometric Mean Titers (GMT)
Geometric Mean Titers (GMT) pre and post-vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
Time frame: pre-vaccination, 21 days post the first vaccination and 21 days post the second vaccination.
Immunogenicity - Seroprotection rate
Seroprotection rate pre and post-vaccination (by the hemagglutination inhibition test - HI), for each intervention group, in adults and older adults.
Time frame: pre-vaccination and 21 days post first vaccination
Immunogenicity - Ratio between the Geometric Mean Titers (rGMT) of antibodies
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.
Time frame: 21 days post the first vaccination
Immunogenicity - Ratio between the Geometric Mean Titers (rGMT) of antibodies
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.
Time frame: 21 days post the second vaccination
Immunogenicity - Seroconversion rate pre and post 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.
Time frame: 21 days post the first vaccination and 21 days post the second vaccination.
Immunogenicity - Seroprotection rate pre and post-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.
Time frame: pre-vaccination, 21 days post the first vaccination and 21 days post the second vaccination
Immunogenicity - Geometric Mean Titers (GMT) pre and post-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.
Time frame: 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
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)
Time frame: 21 days post the second vaccination
Plan to share: No
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Butantan Institute