A Phase 1 interventional study of Grupo 1 - dose 25 μg and Group 2 - 50 μg dose in Severe Acute Respiratory Syndrome (SARS-CoV-2 Virus), sponsored by The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz). Not yet recruiting. Open to participants aged 18 Years to 59 Years. Per ClinicalTrials.gov, last updated 2026-06-10.
Sponsored by The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz) · Phase 1, Interventional, and Treatment
This is a descriptive, open-label, multicenter, non-randomized, uncontrolled phase I clinical study to evaluate the safety, reactogenicity, and immunogenicity of the COVID-19 Vaccine (mRNA) - Bio-Manguinhos/Fiocruz at doses of 25 μg, 50 μg, and 100 μg in healthy adults aged 18 to 59 years. Each study cohort (25 μg, 50 μg, and 100 μg) will initially include a sentinel group of five participants, who will be included sequentially, one by one. This inclusion will allow for an initial integrated risk-benefit assessment, evaluating whether the data from the included participant maintain the risk within acceptable limits for progression.
The inclusion of cohorts, defined by dose, will be carried out in a staggered manner in the following order:
Sentinel group 1 (25 μg dose): Analysis of reactogenicity and safety data from 5 participants, who will be included one at a time and evaluated 48 hours after administration of the investigational product. The safety data from these participants will be obtained 7 days after vaccination and evaluated by the CMDS to allow the inclusion of the remaining 25 participants from this dose, as well as the participants from the sentinel group of the 50 μg dose.
Sentinel group 2 (50 μg dose): Analysis of reactogenicity and safety data from 5 participants, who will be included one at a time and evaluated 48 hours after administration of the investigational product. Safety data from these participants will be obtained 7 days after vaccination and evaluated by the CMDS to allow the inclusion of the remaining 25 participants from this dose, as well as the participants from the sentinel group of the 100 μg dose.
Sentinel Group 3 (100 μg dose): Analysis of reactogenicity and safety data from 5 participants, who will be included one at a time and evaluated 48 hours after administration of the investigational product. Safety data from these participants will be obtained 7 days after vaccination and evaluated by the CMDS to allow the inclusion of the remaining 25 participants in this dose.
At the end of this period, a formal cumulative safety review will be conducted by the Data and Safety Monitoring Committee (CMDS), which will evaluate all available safety data from the sentinel group, including: solicited and unsolicited adverse events; serious adverse events; severe adverse events; vital signs; laboratory data; and any other relevant clinical findings. The CMDS will issue a documented report recommending or not the continuation of the study.
The study population will consist of 90 adult participants who received complete primary vaccination for COVID-19, and at least one additional booster dose, the last booster being an mRNA vaccine approved by ANVISA, administered at least 6 months prior to inclusion.
The study design was based on the European Medicines Agency - EMA guideline, ANVISA-RDC 945/2024 and Law 14.874/2024 [4] and other phase I clinical studies of RNA-based vaccines for COVID-19.
Data from this study will support decisions on whether the candidate vaccine should be further evaluated in advanced phase clinical trials, guide dose selection, and support platform development. If the monovalent candidate induces potentially protective immune responses with an acceptable safety profile, there may be potential to develop future multivalent vaccines to prevent COVID-19 disease based on this platform.
The clinical study will begin immediately after ethical and regulatory approvals. The participant inclusion period is estimated to be 6 months. Follow-up of each participant will require another 6 months. Therefore, the total time required between the first visit of the first participant included and the last visit of the last participant is approximately 12 months.
Description of the Experimental Intervention: The COVID-19 Vaccine (mRNA) - Bio-Manguinhos/Fiocruz is a monovalent vaccine for the prevention of severe cases of COVID-19. The product under investigation consists of a formulation containing messenger ribonucleic acid (mRNA) encoding the Spike protein of the XBB variant of the SARS-CoV-2 virus.
Randomization: There will be no randomization in this study. Blinding/Breaking of Blinding: The study is open-label. There will be no blinding.
376 studies on the registry are indexed under Severe Acute Respiratory Syndrome; 15 are open to participants now.
This study's planned enrollment of 90 is below the median of 145 across 211 interventional studies indexed under Severe Acute Respiratory Syndrome.
Browse Severe Acute Respiratory Syndrome studies →The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz) is the lead sponsor of 28 studies on the registry; 5 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:
Absolute or relative to the mRNA-based COVID-19 vaccine:
changes in screening laboratory tests (visit V1):
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.
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.
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.
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.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
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.
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.
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.
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.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
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.
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.
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.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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.
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.
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.
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.
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.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Group consisting of 30 participants (5 from the sentinel group + 25 participants). This group will receive the experimental COVID-19 vaccine (mRNA) - Bio-Manguinhos/Fiocruz - at a dose of 25 μg.
Biological: Grupo 1 - dose 25 μg
Group consisting of 30 participants (5 from the sentinel group + 25 participants). This group will receive the experimental COVID-19 vaccine (mRNA) - Bio-Manguinhos/Fiocruz - at a dose of 50 μg.
Biological: Group 2 - 50 μg dose
Group consisting of 30 participants (5 from the sentinel group + 25 participants). This group will receive the experimental COVID-19 vaccine (mRNA) - Bio-Manguinhos/Fiocruz - at a dose of 100 μg.
Biological: Group 3 - 100 μg
Administration of the experimental COVID-19 vaccine (mRNA) - Bio-Manguinhos/Fiocruz - at a dose of 25 μg (single intramuscular dose)
Administration of the experimental COVID-19 vaccine (mRNA) - Bio-Manguinhos/Fiocruz - at a dose of 50 μg (single intramuscular dose)
Administration of the experimental COVID-19 vaccine (mRNA) - Bio-Manguinhos/Fiocruz - at a dose of 100 μg (single intramuscular dose)
Safety outcomes following experimental vaccination
Incidence of Treatment-Emergent Adverse Events \[Safety and Tolerability\].
Time frame: Up to 7 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Incidence, severity, intensity, and causality of adverse events reported at 28, 90, and 180 days after vaccination.
Time frame: Reported at 28, 90, and 180 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Increase relative to V0 values of the geometric mean of neutralizing antibody titers against the XBB variant and variants of interest at the time of conducting the study at 7, 28, 90 and 180 days after vaccination.
Time frame: Reported at 7, 28, 90 and 180 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Percentage of participants with an increase of 4 times or more in relation to the V0 values in neutralizing antibody titers against the XBB variant and variants of interest at the time of conducting the study at 7, 28, 90 and 180 days after vaccination.
Time frame: Reported at 7, 28, 90 and 180 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Increase in relation to V0 values of the geometric mean of the titer of total antibodies (IgG) specific to the RBD portion of the XBB S protein at 7, 28, 90 and 180 days after vaccination.
Time frame: Reported at 7, 28, 90 and 180 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Percentage of participants with an increase of 4 times or more compared to V0 values in total antibody levels (IgG) specific to the RBD portion of the XBB S protein at 7, 28, 90, and 180 days after vaccination.
Time frame: Reported at 7, 28, 90 and 180 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Evaluation of the profile of T cells producing IFN-γ, IL-2, and IL-4 in PBMC cultures stimulated with the XBB variant and variants of interest at the time of conducting the study at 7, 28, 90, and 180 days after vaccination.
Time frame: Reported at 7, 28, 90 and 180 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Identification of differentially expressed genes related to vaccine safety, 7 days after vaccination.
Time frame: Reported at 7 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Comparison of serum IL-2, IL-4, IL-5, IL-10, TNF-α, and IFN-γ quantifications with respect to V0 values, 7, 28, 90, and 180 days after vaccination.
Time frame: Reported at 7, 28, 90, and 180 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Comparison of V0 values of the antibody avidity index for XBB and variants of interest at the time of conducting the study at 7, 28, 90, and 180 days after vaccination.
Time frame: Reported at 7, 28, 90, and 180 days after vaccination.
Assessment of cellular and humoral safety and immunity.
Comparison of V0 values of the percentages of cells from the subpopulations of T and B cells in PBMC cultures stimulated with the XBB variant and variants of interest at the time of conducting the study at 7, 28, 90 and 180 days after vaccination.
Time frame: Reported at 7, 28, 90, and 180 days after vaccination.
No study locations are listed for this record.
Plan to share: No
No publications or documents are linked to this record.
Start is estimated for Jul 2026; primary completion for Jul 2027, 12 months later.
Of 18 phase 1 interventional studies under Severe Acute Respiratory Syndrome, half reached primary completion within 10 months of starting (the median), counting those still running; a quarter within 4 and three quarters within 15. This study's planned 12 months is above that.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Severe Acute Respiratory Syndrome →
The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz)