COVID-19Phase 3SARS-CoV-2NCT05507671

The Role of BCG Vaccine in the Clinical Evolution of COVID-19 and in the Efficacy of Anti-SARS-CoV-2 Vaccines

A Phase 3 study testing BCG (Bacillus Calmette-Guérin) vaccine in people with COVID-19, run by Oswaldo Cruz Foundation at 4 sites in Brazil.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record

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Trial summary

Who is it for?: Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for: COVID-19
What is being tested?: BCG (Bacillus Calmette-Guérin) vaccine
Type of treatment: Vaccines
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 556 participants
Where: 4 sitesBrazil
Study dates: 27 May 2021to 31 Dec 2025
Phase: Phase 3
Are there results?: Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
All sexes
Healthy volunteers accepted
Adult, Older adult

Who may be able to join

Never been infected by SARS-Cov-2 - clinical history and absence of anti-SARS-CoV-2 IgM/IgG antibodies by the rapid test (immediate) and by serology test (later confirmation)
Not having been vaccinated against COVID-19
Be at least 18 years old

Who cannot join

Have been vaccinated with BCG less than 6 months ago
Have been vaccinated with BCG more than once in the past
Present any classic contraindications for BCG - pregnancy, breastfeeding, acute febrile illness, severe allergy to one of the components, vaccination with other live vaccines in the last month (measles, yellow fever, herpes zoster), immunosuppression for any cause (congenital, illness, use of corticosteroids or immunosuppressants)
Have had tuberculosis or contacted someone with tuberculosis
Present signs of any current acute illness or have had a severe illness less than 15 days
Present a skin lesion at the vaccine application site (right deltoid muscle)

Show all 10Show fewer

History of severe allergic reactions to any product: urticaria, glottis edema, angioedema, respiratory failure, bronchospasm
History of serious autoimmune diseases: systemic lupus erythematosus, Crohn's disease, ulcerative colitis, multiple sclerosis, hemolytic anemia, ankylosing spondylitis, pemphigus and others
Immunocompromise for any reason (congenital, illness, use of corticosteroids or immunosuppressants)
Presenting a risk comorbidity for severe COVID-19, such as: poorly controlled hypertension, decompensated heart disease (chronic, congenital or ischemic), pulmonary disease (chronic pneumopathy, poorly controlled asthma, chronic interstitial pneumopathy, others ...), disease advanced chronic kidney disease (use of dialysis), transplantation (of solid organs or bone marrow), uncontrolled diabetes

Trial locations and contacts

4 sites in 1 country.

Brazil4 sites

Centro Universitário do Pará
Belém, Pará, 66613-903
Universidade Federal de Juiz de Fora
Juiz de Fora, Minas Gerais, 36036-900
Policlínica Cardoso Fontes
Manaus, Amazonas, 69010-030
Oswaldo Cruz Foundation
Rio de Janeiro, Rio de Janeiro, 21040-360

Other trials in Brazil

About this study

Official title: The Role of the Bacillus Calmette-Guérin Vaccine (BCG) in the Clinical Evolution of COVID-19 and in the Efficacy of Anti-SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) Vaccines

Clinical trial with randomized allocation in two arms (BCG vaccine versus placebo) of volunteers at risk but not yet infected nor vaccinated against SARS-CoV-2. Initially will be evaluated whether BCG has a protective role against severe form of the disease. After participants are vaccinated against COVID-19, it will be evaluated whether BCG favors the vaccine's efficacy. Volunteers will be recruited in three Brazilian states, with at least 250 seronegative in each group. The BCG-trained immunity stimulus will be investigated by assessing cytokines at D0 and D60 in a subsample of 50 participants per group. Until being vaccinated against COVID-19, the participants will be followed for up to 6 months, with visits scheduled every 2 months for interviews and immunoglobulin G (IgG) anti-SARS-CoV-2 antibodies. Those who become symptomatic at any time during the follow-up will be guided and monitored remotely daily until the end of their clinical evolution. After being vaccinated against COVID-19, visits to participants will be adjusted for the time of vaccination (VD), 20 days after the 1st dose (P1) and at least 30 days (P2) after the 2nd dose, with the aim of comparing the efficacy of the anti-SARS-CoV-2 vaccine in the two groups in the short and medium term.

The study's conclusions on the efficacy of BCG in preventing severe COVID-19 will be based on: incidence of SARS-Cov-2 infection (defined as the emergence of IgG over the follow-up period); incidence of illness by COVID-19 (defined as the presence of symptoms among infected participants); intensity and duration of symptoms between cases of COVID-19 and frequency and duration of hospitalizations for COVID-19 in each group. The occurrence, type, frequency and intensity of adverse effects associated with vaccination of adults with BCG will be reported.

The study's conclusions regarding the effect of BCG on efficacy of vaccines against COVID-19 will be based on: frequency of anti-SARS-CoV-2 neutralizing antibodies after the vaccine' 1st and 2nd doses in both groups.

Read the detailed description

OBJECTIVE- To evaluate the role of the BCG vaccine against the severe form of COVID-19 and in improving the efficacy of anti-SARS-CoV-2 vaccines through a two-arm clinical trial comparing BCG versus placebo. Specifically:
Assess whether BCG vaccine is able to stimulate the nonspecific immune response (trained immunity)
Verify whether BCG is able to protect against SARS-CoV-2 infection
Assess whether BCG is able to protect infected with SARS-CoV-2 against illness
Assess whether BCG is able to protect subjects with COVID-19 against its severe form
Evaluate whether BCG can favor the effectiveness of doses of anti-SARS-CoV-2 vaccines
Knowing whether revaccination of adults with BCG causes unexpected adverse reactions
METHODOLOGY: 2.1 STUDY MODEL: Two-arm Clinical Trial - intervention (BCG) versus placebo 2.2 STUDY POPULATION: Volunteers not yet infected with SARS-CoV-2 or vaccinated against COVID-19, who can be essential service workers with frequent contact with the population: workers in health posts, users of the public health network due to others non-serious illnesses, police officers, employees of pharmacies, supermarkets, stores and others Sampling: As the real prevalence of SARS-CoV-2 infection in the eligible population of the different recruitment sites is unknown, a prevalence of 50% was considered (it provides the largest sample size) and estimated that the post-BCG prevalence would decrease at least 10% if its effectiveness to be demonstrated. Thus, it was found a sample of 385 subjects. Considering losses, a minimum of 400 participants will be recruited, with at least 200 in each group. 2.3. INCLUSION CRITERIA:

Never been infected by SARS-Cov-2 - clinical history and absence of anti-SARS-CoV-2 immunoglobulins IgM/IgG antibodies by rapid test (immediate) and serology test (later confirmation)
Not having been vaccinated against COVID-19
Be at least 18 years old 2.4. EXCLUSION CRITERIA: • Have been vaccinated with BCG less than 6 months ago
Have been vaccinated with BCG more than once in the past
Present any classic contraindications for BCG - pregnancy, breastfeeding, acute febrile illness, severe allergy to one of the components, vaccination with other live vaccines in the last month (measles, yellow fever, herpes zoster), immunosuppression for any cause (congenital, illness, use of corticosteroids or immunosuppressants)
Have had tuberculosis or contacted someone with tuberculosis
Present signs of any current acute illness or have had a severe illness less than 15 days
Present a skin lesion at the vaccine application site (right deltoid muscle)
History of severe allergic reactions to any product: urticaria, glottis edema, angioedema, respiratory failure, bronchospasm
History of serious autoimmune diseases: systemic lupus erythematosus, Crohn's disease, ulcerative colitis, multiple sclerosis, hemolytic anemia, ankylosing spondylitis, pemphigus and others
Immunocompromise for any reason: congenital, illness, use of corticosteroids or immunosuppressants
Presenting a risk comorbidity for severe COVID-19: poorly controlled hypertension, decompensated heart disease (chronic, congenital or ischemic), pulmonary disease (chronic pneumopathy, poorly controlled asthma, chronic interstitial pneumopathy, others ...), disease advanced chronic kidney disease (use of dialysis), transplantation (of solid organs or bone marrow), uncontrolled diabetes 2.5. RECRUITMENT OF PARTICIPANTS The volunteers will be recruited in three different Brazilian states - Minas Gerais state (Juiz de Fora city), Amazonas state (Manaus city) and Pará state (Belém city). Their approach will be based on the viability and logistics of each recruitment site, considering the local dynamics of anti-COVID-19 vaccination by age. Those who meet the inclusion criteria and accept to participate in the study, must sign the Informed Consent Form (ICF). By lot, the participant will be allocated to Group 1 or 2, to receive placebo (BCG solvent) or BCG vaccine. 2.6. INCLUSION AND FOLLOW-UP OF PARTICIPANTS 2.6.a -- Evaluation of BCG against the severe form of COVID-19: The subjects will be contacted at D0 (day of inclusion and intervention), D60, D120 and D180, as well as on any day of symptom onset in order to assess the presence and evolution of a SARS-CoV-2 infection. A standardized questionnaire will be developed and tablets will be programmed with the REDCap software to conduct interviews at each visit to investigate demographic data, past and current illnesses, vaccination history, risk activities and symptoms suggestive of COVID-19. Participants will be instructed to inform the team as soon as present any suspicious symptoms. In each scheduled visit, the participants will also undergo a venous blood collection to:
On D0 - Search of IgM/IgG antibodies by rapid test and IgG by serology (enzyme immunoassay-ELISA) in all subjects and search of pro-inflammatory cytokines Tumor Necrosis Factor α (TNF-α), interferon γ (IFN-γ), interleukin (IL)1β, IL-4, IL-6 and IL-10 in 50 participants from each group.
On D60 - Search of anti-SARS-CoV-2 IgG by ELISA in all participants and paired cytokine search (participants who did it on D0).
On D120 and D180 - Search of anti-SARS-CoV-2 IgG by ELISA.
If Symptom - Daily follow-up to guide diagnostic confirmation of SARS-CoV-2 infection in the local health network and to monitor clinical evolution. Furthermore, the patient will fill a table of daily symptoms, which will be collected at the next scheduled visit. In case of hospitalization, data of clinical evolution will be obtained from medical records. 2.6.b -- Evaluation of BCG´s capacity to improve the vaccine anti-SARS-CoV-2 efficacy: From the moment the participants are vaccinated against covid-19, the visits will be adjusted to the vaccination schedule, as follows:
VD - at the time of 1st dose of the vaccine
P1 - 20 days after the 1st dose
P2 - at least 30 days after the 2nd dose On all these occasions, neutralizing anti-SARS-CoV-2 antibodies will be tested in all participants. 2.7. INTERVENTION The inclusion in the BCG or Placebo Group will be done by lot, whose knowledge will be restricted to the main researcher and the professional who will perform the intervention. The participants and the technician who will carry out the laboratory tests will not know it.
BCG Group - BCG vaccine (live attenuated Mycobacterium bovis (Bacillus Calmette-Guérin) from the Serum Institute of India Ltd. Intradermal dose of 0.1 ml applied at the distal insertion of the right deltoid. Expected adverse effects of BCG can be tenderness, swelling and a reddened papule at the site which will become a 1 cm-diameter liquid ulcer that will close in 2 or 3 months, almost always leaving a scar of the same size. Other possible side effects are: headache, malaise, fever, ulcer greater than 1 cm, delayed healing (up to 6 months), enlarged lymph nodes. A rare serious complication is local or axillary node abscess due to error in administration with subcutaneous deposit of the vaccine. Thus, BCG will be managed by a rigorously trained professional. There is also reference to the spread of the vaccine bacillus causing organ damage in immunocompromised individuals (an exclusion criterion). Subjects with a severe reaction will receive adequate follow-up and treatment. -Placebo Group - Application of 0.1 ml intradermal of BCG vaccine solvent. 2.8. INFECTION DETECTION Current SARS-Cov-2 infection will be identified by rapid test to detect IgM/IgG antibodies (only on D0 as an exclusion criterion) and by serology to detect IgG antibodies on every visit. Through positivity for IgG throughout the follow-up, the investigators will identify the participants who became infected between visits throughout the follow-up. 2.9. CLINICAL EVOLUTION - The clinical status of symptomatic infected people will be defined as:
MILD STATUS (Influenza Syndrome-SG) - Fever accompanied by cough or sore throat or loss of smell/taste and at least one of the following symptoms: headache, myalgia or arthralgia. Less common symptoms may be: body pain, nasal congestion, diarrhea, abdominal pain, rash, discolored fingers and toes, conjunctivitis.
MODERATE STATUS - Tiredness or slight difficulty in breathing on small efforts and/or increase in the intensity of the underlying symptoms after 4 days of illness and/or increase in the number of underlying symptoms after 4 days of illness and/or persistence of symptoms for more than one week.
SERIOUS STATUS (Severe Acute Respiratory Syndrome) - SG associated with deficit in the respiratory system (difficulty breathing, cyanosis, oxygen saturation <95%, tachypnea, partial pressures of oxygen in alveolar gas/fraction of inspired oxygen (PaO2/FiO2) <300 and/or pulmonary infiltration >50% in 24- 48h), deficit in the cardiovascular system (hypotension, weak pulse) or change in mental status.
CRITICAL STATUS - Respiratory failure, septic shock and / or multiple organ dysfunction, loss of speech or movement. 2.10. EVALUATION OF THE HUMORAL RESPONSE PROFILE At D0, as an inclusion criterion, the rapid test for detection of anti-SARS-CoV-2 IgG/IgM antibodies (TR COVID-19 IgM/IgG "BioManguinhos-Fiocruz") with 100% specificity for IgM and IgG and sensitivity of 85.7% (4-7 days) and 90% (> 8 days) for IgM and 92.8% (4-7 days) and 90% (>8 days) for IgG. Also on D0 and on all visiting days and in case of symptoms, IgG will be detected by a commercial enzyme immunoassay (recombinant ELISA - "Euroimmun Brasil Medicina Diagnóstica") with the S1 subdomain of the Spike protein as the capture antigen, in order to detect infections occurred between visits (seroconversion). To assess the efficacy of anti-SARS-CoV-2 vaccines, anti-SARS-CoV-2 neutralizing antibodies will be investigated using the SARS-CoV-2 Surrogate Virus Neutralization Test-sVNT ("Genscript") kit, which provides qualitative and semi-quatitative (titer in UI/ml) results. This investigation will be done 20 days after the 1st dose and at least 1 month after the 2nd dose of the vaccine. 2.11. CYTOKINE ANALYSIS - It will be measure the proinflammatory cytokines IL-1β, IL-4, IL-6, IL-10, TNF-α (R\&D Systems) and IFN-γ ("Sanquin") at D0 and D60 to assess the effectiveness of BCG in stimulating the non-specific immune response. 2.12. ETHICAL ISSUES - The project was approved by the National Commission for Ethics in Research with Human Beings-CONEP. Volunteers who wished to participate signed the Informed Consent Form. An Independent Data and Safety Monitoring Committee (IDSMC) will monitor the study to ensure it is ethically non-violent and data credible, and may recommend modifications or suspension of the study if necessary. Through the Research Electronic Data Capture-REDCap software, a data manager will provide information about the study progress any time it be requested. The results of the exams will be provided to the participants. Intense reaction to BCG will receive due care from the research team and will be notified to CONEP and IDSMC within 24 hours. Participants will be encouraged to receive the COVID-19 vaccine when it becomes available to them. 2.14. STATISTICAL ANALYSIS OF RESULTS - Through the Statistical Package for the Social Sciences (IBM SPSS v.22) and Stata (v.14.0) programs, the outcomes will be analyzed comparatively between the groups, being defined as failures. Analyzes will be performed for the intention-to-treat population (total recruits) and per protocol population (with full follow-up) using the Kaplan-Meier method. Proportions will be calculated with 95% confidence intervals and compared by Chi2 and Fisher's exact test. Survival curves will be compared by log rank test. Logistic regression will identify the set of independent variables that can explain the binary dependent variables, such as serological reactivity.

Conditions: COVID-19
Being tested: BCG (Bacillus Calmette-Guérin) vaccine, Placebo
Keywords: COVID-19, SARS-CoV-2, BCG vaccine, Bacillus Calmette-Guérin, clinical trials, trained immunity
Medical subject headings: COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

BCG (Bacillus Calmette-Guérin) vaccineBiological
Application of BCG vaccine (0.1 ml intradermal) in the right arm deltoid insertion
PlaceboOther
Application of BCG solvent (0.1 ml intradermal) in the right arm deltoid insertion

Study groups in NCT05507671
Study group	Role	What they receive
BCG vaccine	Active comparator	BCG (Bacillus Calmette-Guérin) vaccine - 0,1ml intradermal Receives: Biological: BCG (Bacillus Calmette-Guérin) vaccine
Placebo	Placebo comparator	Solvent of BCG vaccine - 0,1ml intradermal Receives: Other: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

Incidence of SARS-Cov-2 infection in both groups over the follow-up
Appearance of IgG antibodies (seroconversion) in the participants not yet vaccinated against COVID-19
Measured: Up to six months from recruitment day
Incidence of illness by COVID-19 in both groups over the follow-up
Presence of symptoms among subjects not vaccinated against COVID-19 diagnosed with infection after D0 or seroconverted
Measured: Up to six months from recruitment day
Intensity of the efficacy of the first dose of the vaccine against COVID-19
Comparison of groups regarding frequency and titer (UI/ml) of anti-SARS-CoV-2 neutralizing antibodies after first dose of the specific vaccine, through the qualitative and semi-quatitative "SARS-CoV-2 Surrogate Virus Neutralization Test (sVNT)" Genscript Kit
Measured: Up to six months from recruitment day
Duration of the efficacy of the second dose of the vaccine against COVID-19
Comparison of groups regarding frequency and titer (UI/ml) of anti-SARS-CoV-2 neutralizing antibodies after second dose of the specific vaccine, through the qualitative and semi-quatitative "SARS-CoV-2 Surrogate Virus Neutralization Test (sVNT)" Genscript Kit
Measured: One year from recruitment day

Secondary outcomes (3)

Intensity of clinical presentation of SARS-CoV-2 infection in both groups over the follow-up
Comparison of groups regarding the frequency of infected with mild, moderate, serious or critical symptoms (according to detailed description in item 2.9-Clinical Evolution) and deaths by COVID-19 during the follow-up. The information will be obtained through daily telephone interview, self-completion of a questionnaire and hospitalization data.
Measured: One year from recruitment day
Duration of symptoms among participants with COVID-19
Comparison of groups regarding the duration (number of days) of symptoms among participants who acquire COVID-19. The information will be obtained through daily telephone interview, self-completion of a questionnaire and hospitalization data
Measured: Six months from recruitment day
Serum levels of cytokines after BCG vaccine stimulus (Trained Immunity effect)
Comparison of serum concentrations (pg/mL) of cytokines TNF-α, IFN-γ, IL-1β, IL-4, IL-6 and IL-10 at D0 versus D60 of 50 participants of BCG group compared to 50 participants of placebo group
Measured: Two months from recruitment day

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

27 May 202131 Dec 2025

First posted19 Aug 2022
Study start27 May 2021
Primary completion31 Jul 2023
Study completion31 Dec 2025 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (41)Papers the sponsor has linked to this study.
Other trials for COVID-19Studies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 3
Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Model description: Two-arm study, BCG vaccine versus placebo, to assess the effect of BCG in preventing severe form of covid19 and improving the efficacy of anti-SARS-CoV-2 vaccines
Masking: Double blind
Who is masked: Participant, Outcomes assessor
Enrolment: 556 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05507671
Sponsor's protocol ID: BCG-COVID/484016302711489/2020
Acronym: SARS-CoV-2
Status last verified: Mar 2025
First submitted: 27 May 2021
Last updated: 8 Aug 2025
Results posted: No
Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Publications

Wu F, Zhao S, Yu B, Chen YM, Wang W, Song ZG, Hu Y, Tao ZW, Tian JH, Pei YY, Yuan ML, Zhang YL, Dai FH, Liu Y, Wang QM, Zheng JJ, Xu L, Holmes EC, Zhang YZ. A new coronavirus associated with human respiratory disease in China. Nature. 2020 Mar;579(7798):265-269. doi: 10.1038/s41586-020-2008-3. Epub 2020 Feb 3.
PubMed 32015508
Pan Y, Zhang D, Yang P, Poon LLM, Wang Q. Viral load of SARS-CoV-2 in clinical samples. Lancet Infect Dis. 2020 Apr;20(4):411-412. doi: 10.1016/S1473-3099(20)30113-4. Epub 2020 Feb 24. No abstract available.
PubMed 32105638
Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, Qiu Y, Wang J, Liu Y, Wei Y, Xia J, Yu T, Zhang X, Zhang L. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet. 2020 Feb 15;395(10223):507-513. doi: 10.1016/S0140-6736(20)30211-7. Epub 2020 Jan 30.
PubMed 32007143
Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W; China Novel Coronavirus Investigating and Research Team. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med. 2020 Feb 20;382(8):727-733. doi: 10.1056/NEJMoa2001017. Epub 2020 Jan 24.
PubMed 31978945
Zhao J, Yuan Q, Wang H, Liu W, Liao X, Su Y, Wang X, Yuan J, Li T, Li J, Qian S, Hong C, Wang F, Liu Y, Wang Z, He Q, Li Z, He B, Zhang T, Fu Y, Ge S, Liu L, Zhang J, Xia N, Zhang Z. Antibody Responses to SARS-CoV-2 in Patients With Novel Coronavirus Disease 2019. Clin Infect Dis. 2020 Nov 19;71(16):2027-2034. doi: 10.1093/cid/ciaa344.
PubMed 32221519
Wu Z, McGoogan JM. Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72 314 Cases From the Chinese Center for Disease Control and Prevention. JAMA. 2020 Apr 7;323(13):1239-1242. doi: 10.1001/jama.2020.2648. No abstract available.
PubMed 32091533
Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, Zhang L, Fan G, Xu J, Gu X, Cheng Z, Yu T, Xia J, Wei Y, Wu W, Xie X, Yin W, Li H, Liu M, Xiao Y, Gao H, Guo L, Xie J, Wang G, Jiang R, Gao Z, Jin Q, Wang J, Cao B. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020 Feb 15;395(10223):497-506. doi: 10.1016/S0140-6736(20)30183-5. Epub 2020 Jan 24.
PubMed 31986264
Corman VM, Landt O, Kaiser M, Molenkamp R, Meijer A, Chu DK, Bleicker T, Brunink S, Schneider J, Schmidt ML, Mulders DG, Haagmans BL, van der Veer B, van den Brink S, Wijsman L, Goderski G, Romette JL, Ellis J, Zambon M, Peiris M, Goossens H, Reusken C, Koopmans MP, Drosten C. Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. Euro Surveill. 2020 Jan;25(3):2000045. doi: 10.2807/1560-7917.ES.2020.25.3.2000045.
PubMed 31992387
Gates B. Responding to Covid-19 - A Once-in-a-Century Pandemic? N Engl J Med. 2020 Apr 30;382(18):1677-1679. doi: 10.1056/NEJMp2003762. Epub 2020 Feb 28. No abstract available.
PubMed 32109012
Hopman J, Allegranzi B, Mehtar S. Managing COVID-19 in Low- and Middle-Income Countries. JAMA. 2020 Apr 28;323(16):1549-1550. doi: 10.1001/jama.2020.4169. No abstract available.
PubMed 32176764
Wang M, Cao R, Zhang L, Yang X, Liu J, Xu M, Shi Z, Hu Z, Zhong W, Xiao G. Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro. Cell Res. 2020 Mar;30(3):269-271. doi: 10.1038/s41422-020-0282-0. Epub 2020 Feb 4. No abstract available.
PubMed 32020029
Gautret P, Lagier JC, Parola P, Hoang VT, Meddeb L, Mailhe M, Doudier B, Courjon J, Giordanengo V, Vieira VE, Tissot Dupont H, Honore S, Colson P, Chabriere E, La Scola B, Rolain JM, Brouqui P, Raoult D. RETRACTED: Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial. Int J Antimicrob Agents. 2020 Jul;56(1):105949. doi: 10.1016/j.ijantimicag.2020.105949. Epub 2020 Mar 20.
PubMed 32205204
Mahase E. Covid-19: what treatments are being investigated? BMJ. 2020 Mar 26;368:m1252. doi: 10.1136/bmj.m1252. No abstract available.
PubMed 32217607
Colditz GA, Berkey CS, Mosteller F, Brewer TF, Wilson ME, Burdick E, Fineberg HV. The efficacy of bacillus Calmette-Guerin vaccination of newborns and infants in the prevention of tuberculosis: meta-analyses of the published literature. Pediatrics. 1995 Jul;96(1 Pt 1):29-35.
PubMed 7596718
Mangtani P, Abubakar I, Ariti C, Beynon R, Pimpin L, Fine PE, Rodrigues LC, Smith PG, Lipman M, Whiting PF, Sterne JA. Protection by BCG vaccine against tuberculosis: a systematic review of randomized controlled trials. Clin Infect Dis. 2014 Feb;58(4):470-80. doi: 10.1093/cid/cit790. Epub 2013 Dec 13.
PubMed 24336911

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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Study at a glance

From the registry record, last updated by the sponsor on 8 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: The Role of the Bacillus Calmette-Guérin Vaccine (BCG) in the Clinical Evolution of COVID-19 and in the Efficacy of Anti-SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) Vaccines
ClinicalTrials.gov ID: NCT05507671
Acronym / sponsor ID: SARS-CoV-2 / BCG-COVID/484016302711489/2020
Conditions: COVID-19
Keywords: COVID-19, SARS-CoV-2, BCG vaccine, Bacillus Calmette-Guérin, clinical trials, trained immunity
Phase: Phase 3
Study type: Interventional
Recruitment status: Active, not recruiting
Enrolment: 556 participants (estimated)
Lead sponsor: Oswaldo Cruz FoundationUniversity, hospital or other
Collaborators: University of Sao Paulo, Federal University of Juiz de Fora
Study start: 27 May 2021 (actual)
Primary completion: 31 Jul 2023 (actual)
Study completion: 31 Dec 2025 (estimated)
First posted: 19 Aug 2022 (actual)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

OBJECTIVE- To evaluate the role of the BCG vaccine against the severe form of COVID-19 and in improving the efficacy of anti-SARS-CoV-2 vaccines through a two-arm clinical trial comparing BCG versus placebo. Specifically:
Assess whether BCG vaccine is able to stimulate the nonspecific immune response (trained immunity)
Verify whether BCG is able to protect against SARS-CoV-2 infection
Assess whether BCG is able to protect infected with SARS-CoV-2 against illness
Assess whether BCG is able to protect subjects with COVID-19 against its severe form
Evaluate whether BCG can favor the effectiveness of doses of anti-SARS-CoV-2 vaccines
Knowing whether revaccination of adults with BCG causes unexpected adverse reactions
METHODOLOGY: 2.1 STUDY MODEL: Two-arm Clinical Trial - intervention (BCG) versus placebo 2.2 STUDY POPULATION: Volunteers not yet infected with SARS-CoV-2 or vaccinated against COVID-19, who can be essential service workers with frequent contact with the population: workers in health posts, users of the public health network due to others non-serious illnesses, police officers, employees of pharmacies, supermarkets, stores and others Sampling: As the real prevalence of SARS-CoV-2 infection in the eligible population of the different recruitment sites is unknown, a prevalence of 50% was considered (it provides the largest sample size) and estimated that the post-BCG prevalence would decrease at least 10% if its effectiveness to be demonstrated. Thus, it was found a sample of 385 subjects. Considering losses, a minimum of 400 participants will be recruited, with at least 200 in each group. 2.3. INCLUSION CRITERIA:

Never been infected by SARS-Cov-2 - clinical history and absence of anti-SARS-CoV-2 immunoglobulins IgM/IgG antibodies by rapid test (immediate) and serology test (later confirmation)
Not having been vaccinated against COVID-19
Be at least 18 years old 2.4. EXCLUSION CRITERIA: • Have been vaccinated with BCG less than 6 months ago
Have been vaccinated with BCG more than once in the past
Present any classic contraindications for BCG - pregnancy, breastfeeding, acute febrile illness, severe allergy to one of the components, vaccination with other live vaccines in the last month (measles, yellow fever, herpes zoster), immunosuppression for any cause (congenital, illness, use of corticosteroids or immunosuppressants)
Have had tuberculosis or contacted someone with tuberculosis
Present signs of any current acute illness or have had a severe illness less than 15 days
Present a skin lesion at the vaccine application site (right deltoid muscle)
History of severe allergic reactions to any product: urticaria, glottis edema, angioedema, respiratory failure, bronchospasm
History of serious autoimmune diseases: systemic lupus erythematosus, Crohn's disease, ulcerative colitis, multiple sclerosis, hemolytic anemia, ankylosing spondylitis, pemphigus and others
Immunocompromise for any reason: congenital, illness, use of corticosteroids or immunosuppressants
Presenting a risk comorbidity for severe COVID-19: poorly controlled hypertension, decompensated heart disease (chronic, congenital or ischemic), pulmonary disease (chronic pneumopathy, poorly controlled asthma, chronic interstitial pneumopathy, others ...), disease advanced chronic kidney disease (use of dialysis), transplantation (of solid organs or bone marrow), uncontrolled diabetes 2.5. RECRUITMENT OF PARTICIPANTS The volunteers will be recruited in three different Brazilian states - Minas Gerais state (Juiz de Fora city), Amazonas state (Manaus city) and Pará state (Belém city). Their approach will be based on the viability and logistics of each recruitment site, considering the local dynamics of anti-COVID-19 vaccination by age. Those who meet the inclusion criteria and accept to participate in the study, must sign the Informed Consent Form (ICF). By lot, the participant will be allocated to Group 1 or 2, to receive placebo (BCG solvent) or BCG vaccine. 2.6. INCLUSION AND FOLLOW-UP OF PARTICIPANTS 2.6.a -- Evaluation of BCG against the severe form of COVID-19: The subjects will be contacted at D0 (day of inclusion and intervention), D60, D120 and D180, as well as on any day of symptom onset in order to assess the presence and evolution of a SARS-CoV-2 infection. A standardized questionnaire will be developed and tablets will be programmed with the REDCap software to conduct interviews at each visit to investigate demographic data, past and current illnesses, vaccination history, risk activities and symptoms suggestive of COVID-19. Participants will be instructed to inform the team as soon as present any suspicious symptoms. In each scheduled visit, the participants will also undergo a venous blood collection to:
On D0 - Search of IgM/IgG antibodies by rapid test and IgG by serology (enzyme immunoassay-ELISA) in all subjects and search of pro-inflammatory cytokines Tumor Necrosis Factor α (TNF-α), interferon γ (IFN-γ), interleukin (IL)1β, IL-4, IL-6 and IL-10 in 50 participants from each group.
On D60 - Search of anti-SARS-CoV-2 IgG by ELISA in all participants and paired cytokine search (participants who did it on D0).
On D120 and D180 - Search of anti-SARS-CoV-2 IgG by ELISA.
If Symptom - Daily follow-up to guide diagnostic confirmation of SARS-CoV-2 infection in the local health network and to monitor clinical evolution. Furthermore, the patient will fill a table of daily symptoms, which will be collected at the next scheduled visit. In case of hospitalization, data of clinical evolution will be obtained from medical records. 2.6.b -- Evaluation of BCG´s capacity to improve the vaccine anti-SARS-CoV-2 efficacy: From the moment the participants are vaccinated against covid-19, the visits will be adjusted to the vaccination schedule, as follows:
VD - at the time of 1st dose of the vaccine
P1 - 20 days after the 1st dose
P2 - at least 30 days after the 2nd dose On all these occasions, neutralizing anti-SARS-CoV-2 antibodies will be tested in all participants. 2.7. INTERVENTION The inclusion in the BCG or Placebo Group will be done by lot, whose knowledge will be restricted to the main researcher and the professional who will perform the intervention. The participants and the technician who will carry out the laboratory tests will not know it.
BCG Group - BCG vaccine (live attenuated Mycobacterium bovis (Bacillus Calmette-Guérin) from the Serum Institute of India Ltd. Intradermal dose of 0.1 ml applied at the distal insertion of the right deltoid. Expected adverse effects of BCG can be tenderness, swelling and a reddened papule at the site which will become a 1 cm-diameter liquid ulcer that will close in 2 or 3 months, almost always leaving a scar of the same size. Other possible side effects are: headache, malaise, fever, ulcer greater than 1 cm, delayed healing (up to 6 months), enlarged lymph nodes. A rare serious complication is local or axillary node abscess due to error in administration with subcutaneous deposit of the vaccine. Thus, BCG will be managed by a rigorously trained professional. There is also reference to the spread of the vaccine bacillus causing organ damage in immunocompromised individuals (an exclusion criterion). Subjects with a severe reaction will receive adequate follow-up and treatment. -Placebo Group - Application of 0.1 ml intradermal of BCG vaccine solvent. 2.8. INFECTION DETECTION Current SARS-Cov-2 infection will be identified by rapid test to detect IgM/IgG antibodies (only on D0 as an exclusion criterion) and by serology to detect IgG antibodies on every visit. Through positivity for IgG throughout the follow-up, the investigators will identify the participants who became infected between visits throughout the follow-up. 2.9. CLINICAL EVOLUTION - The clinical status of symptomatic infected people will be defined as:
MILD STATUS (Influenza Syndrome-SG) - Fever accompanied by cough or sore throat or loss of smell/taste and at least one of the following symptoms: headache, myalgia or arthralgia. Less common symptoms may be: body pain, nasal congestion, diarrhea, abdominal pain, rash, discolored fingers and toes, conjunctivitis.
MODERATE STATUS - Tiredness or slight difficulty in breathing on small efforts and/or increase in the intensity of the underlying symptoms after 4 days of illness and/or increase in the number of underlying symptoms after 4 days of illness and/or persistence of symptoms for more than one week.
SERIOUS STATUS (Severe Acute Respiratory Syndrome) - SG associated with deficit in the respiratory system (difficulty breathing, cyanosis, oxygen saturation <95%, tachypnea, partial pressures of oxygen in alveolar gas/fraction of inspired oxygen (PaO2/FiO2) <300 and/or pulmonary infiltration >50% in 24- 48h), deficit in the cardiovascular system (hypotension, weak pulse) or change in mental status.
CRITICAL STATUS - Respiratory failure, septic shock and / or multiple organ dysfunction, loss of speech or movement. 2.10. EVALUATION OF THE HUMORAL RESPONSE PROFILE At D0, as an inclusion criterion, the rapid test for detection of anti-SARS-CoV-2 IgG/IgM antibodies (TR COVID-19 IgM/IgG "BioManguinhos-Fiocruz") with 100% specificity for IgM and IgG and sensitivity of 85.7% (4-7 days) and 90% (> 8 days) for IgM and 92.8% (4-7 days) and 90% (>8 days) for IgG. Also on D0 and on all visiting days and in case of symptoms, IgG will be detected by a commercial enzyme immunoassay (recombinant ELISA - "Euroimmun Brasil Medicina Diagnóstica") with the S1 subdomain of the Spike protein as the capture antigen, in order to detect infections occurred between visits (seroconversion). To assess the efficacy of anti-SARS-CoV-2 vaccines, anti-SARS-CoV-2 neutralizing antibodies will be investigated using the SARS-CoV-2 Surrogate Virus Neutralization Test-sVNT ("Genscript") kit, which provides qualitative and semi-quatitative (titer in UI/ml) results. This investigation will be done 20 days after the 1st dose and at least 1 month after the 2nd dose of the vaccine. 2.11. CYTOKINE ANALYSIS - It will be measure the proinflammatory cytokines IL-1β, IL-4, IL-6, IL-10, TNF-α (R\&D Systems) and IFN-γ ("Sanquin") at D0 and D60 to assess the effectiveness of BCG in stimulating the non-specific immune response. 2.12. ETHICAL ISSUES - The project was approved by the National Commission for Ethics in Research with Human Beings-CONEP. Volunteers who wished to participate signed the Informed Consent Form. An Independent Data and Safety Monitoring Committee (IDSMC) will monitor the study to ensure it is ethically non-violent and data credible, and may recommend modifications or suspension of the study if necessary. Through the Research Electronic Data Capture-REDCap software, a data manager will provide information about the study progress any time it be requested. The results of the exams will be provided to the participants. Intense reaction to BCG will receive due care from the research team and will be notified to CONEP and IDSMC within 24 hours. Participants will be encouraged to receive the COVID-19 vaccine when it becomes available to them. 2.14. STATISTICAL ANALYSIS OF RESULTS - Through the Statistical Package for the Social Sciences (IBM SPSS v.22) and Stata (v.14.0) programs, the outcomes will be analyzed comparatively between the groups, being defined as failures. Analyzes will be performed for the intention-to-treat population (total recruits) and per protocol population (with full follow-up) using the Kaplan-Meier method. Proportions will be calculated with 95% confidence intervals and compared by Chi2 and Fisher's exact test. Survival curves will be compared by log rank test. Logistic regression will identify the set of independent variables that can explain the binary dependent variables, such as serological reactivity.

Study design

Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Masking: Double blind (participant, outcomes assessor)
Number of arms: 2
Model description: Two-arm study, BCG vaccine versus placebo, to assess the effect of BCG in preventing severe form of covid19 and improving the efficacy of anti-SARS-CoV-2 vaccines

Arm	Type	Receives
BCG vaccine	Active comparator	Biological: BCG (Bacillus Calmette-Guérin) vaccineBCG (Bacillus Calmette-Guérin) vaccine - 0,1ml intradermal
Placebo	Placebo comparator	Other: PlaceboSolvent of BCG vaccine - 0,1ml intradermal

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult

Key inclusion criteria (3 listed)

Never been infected by SARS-Cov-2 - clinical history and absence of anti-SARS-CoV-2 IgM/IgG antibodies by the rapid test (immediate) and by serology test (later confirmation)
Not having been vaccinated against COVID-19
Be at least 18 years old

Key exclusion criteria (10 listed)

Have been vaccinated with BCG less than 6 months ago
Have been vaccinated with BCG more than once in the past
Present any classic contraindications for BCG - pregnancy, breastfeeding, acute febrile illness, severe allergy to one of the components, vaccination with other live vaccines in the last month (measles, yellow fever, herpes zoster), immunosuppression for any cause (congenital, illness, use of corticosteroids or immunosuppressants)
Have had tuberculosis or contacted someone with tuberculosis
Present signs of any current acute illness or have had a severe illness less than 15 days

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
BCG (Bacillus Calmette-Guérin) vaccineApplication of BCG vaccine (0.1 ml intradermal) in the right arm deltoid insertion	Biological	BCG vaccine
PlaceboApplication of BCG solvent (0.1 ml intradermal) in the right arm deltoid insertion	Other	Placebo

Primary outcome

Incidence of SARS-Cov-2 infection in both groups over the follow-up
Time frame: Up to six months from recruitment day
Appearance of IgG antibodies (seroconversion) in the participants not yet vaccinated against COVID-19
Incidence of illness by COVID-19 in both groups over the follow-up
Time frame: Up to six months from recruitment day
Presence of symptoms among subjects not vaccinated against COVID-19 diagnosed with infection after D0 or seroconverted
Intensity of the efficacy of the first dose of the vaccine against COVID-19
Time frame: Up to six months from recruitment day
Comparison of groups regarding frequency and titer (UI/ml) of anti-SARS-CoV-2 neutralizing antibodies after first dose of the specific vaccine, through the qualitative and semi-quatitative "SARS-CoV-2 Surrogate Virus Neutralization Test (sVNT)" Genscript Kit
Duration of the efficacy of the second dose of the vaccine against COVID-19
Time frame: One year from recruitment day
Comparison of groups regarding frequency and titer (UI/ml) of anti-SARS-CoV-2 neutralizing antibodies after second dose of the specific vaccine, through the qualitative and semi-quatitative "SARS-CoV-2 Surrogate Virus Neutralization Test (sVNT)" Genscript Kit

3 secondary outcomes

Intensity of clinical presentation of SARS-CoV-2 infection in both groups over the follow-up
Time frame: One year from recruitment day
Duration of symptoms among participants with COVID-19
Time frame: Six months from recruitment day
Serum levels of cytokines after BCG vaccine stimulus (Trained Immunity effect)
Time frame: Two months from recruitment day

Results and safety

This study is still under way. Results are not available in the source record yet.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 8 Aug 2025.
Background: PubMed 32015508Wu F, Zhao S, Yu B, Chen YM, Wang W, Song ZG, Hu Y, Tao ZW, Tian JH, Pei YY, Yuan ML, Zhang YL, Dai FH, Liu Y, Wang QM, Zheng JJ, Xu L, Holmes EC, Zhang YZ. A new coronavirus associated with human respiratory disease in China. Nature. 2020 Mar;579(7798):265-269. doi: 10.1038/s41586-020-2008-3. Epub 2020 Feb 3.
Background: PubMed 32105638Pan Y, Zhang D, Yang P, Poon LLM, Wang Q. Viral load of SARS-CoV-2 in clinical samples. Lancet Infect Dis. 2020 Apr;20(4):411-412. doi: 10.1016/S1473-3099(20)30113-4. Epub 2020 Feb 24. No abstract available.
Background: PubMed 32007143Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, Qiu Y, Wang J, Liu Y, Wei Y, Xia J, Yu T, Zhang X, Zhang L. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet. 2020 Feb 15;395(10223):507-513. doi: 10.1016/S0140-6736(20)30211-7. Epub 2020 Jan 30.
Background: PubMed 31978945Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W; China Novel Coronavirus Investigating and Research Team. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med. 2020 Feb 20;382(8):727-733. doi: 10.1056/NEJMoa2001017. Epub 2020 Jan 24.
Background: PubMed 32221519Zhao J, Yuan Q, Wang H, Liu W, Liao X, Su Y, Wang X, Yuan J, Li T, Li J, Qian S, Hong C, Wang F, Liu Y, Wang Z, He Q, Li Z, He B, Zhang T, Fu Y, Ge S, Liu L, Zhang J, Xia N, Zhang Z. Antibody Responses to SARS-CoV-2 in Patients With Novel Coronavirus Disease 2019. Clin Infect Dis. 2020 Nov 19;71(16):2027-2034. doi: 10.1093/cid/ciaa344.
Background: PubMed 32091533Wu Z, McGoogan JM. Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72 314 Cases From the Chinese Center for Disease Control and Prevention. JAMA. 2020 Apr 7;323(13):1239-1242. doi: 10.1001/jama.2020.2648. No abstract available.
Background: PubMed 31986264Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, Zhang L, Fan G, Xu J, Gu X, Cheng Z, Yu T, Xia J, Wei Y, Wu W, Xie X, Yin W, Li H, Liu M, Xiao Y, Gao H, Guo L, Xie J, Wang G, Jiang R, Gao Z, Jin Q, Wang J, Cao B. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020 Feb 15;395(10223):497-506. doi: 10.1016/S0140-6736(20)30183-5. Epub 2020 Jan 24.
Background: PubMed 31992387Corman VM, Landt O, Kaiser M, Molenkamp R, Meijer A, Chu DK, Bleicker T, Brunink S, Schneider J, Schmidt ML, Mulders DG, Haagmans BL, van der Veer B, van den Brink S, Wijsman L, Goderski G, Romette JL, Ellis J, Zambon M, Peiris M, Goossens H, Reusken C, Koopmans MP, Drosten C. Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. Euro Surveill. 2020 Jan;25(3):2000045. doi: 10.2807/1560-7917.ES.2020.25.3.2000045.
Background: PubMed 32109012Gates B. Responding to Covid-19 - A Once-in-a-Century Pandemic? N Engl J Med. 2020 Apr 30;382(18):1677-1679. doi: 10.1056/NEJMp2003762. Epub 2020 Feb 28. No abstract available.
Background: PubMed 32176764Hopman J, Allegranzi B, Mehtar S. Managing COVID-19 in Low- and Middle-Income Countries. JAMA. 2020 Apr 28;323(16):1549-1550. doi: 10.1001/jama.2020.4169. No abstract available.
Background: PubMed 32020029Wang M, Cao R, Zhang L, Yang X, Liu J, Xu M, Shi Z, Hu Z, Zhong W, Xiao G. Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro. Cell Res. 2020 Mar;30(3):269-271. doi: 10.1038/s41422-020-0282-0. Epub 2020 Feb 4. No abstract available.
Background: PubMed 32205204Gautret P, Lagier JC, Parola P, Hoang VT, Meddeb L, Mailhe M, Doudier B, Courjon J, Giordanengo V, Vieira VE, Tissot Dupont H, Honore S, Colson P, Chabriere E, La Scola B, Rolain JM, Brouqui P, Raoult D. RETRACTED: Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial. Int J Antimicrob Agents. 2020 Jul;56(1):105949. doi: 10.1016/j.ijantimicag.2020.105949. Epub 2020 Mar 20.
Coronavirus World Health Organization (WHO) dataLink provided by the sponsor.
Coronavirus dataLink provided by the sponsor.
Cases of coronavirus in BrazilLink provided by the sponsor.
Number of coronavirus cases in BrazilLink provided by the sponsor.
COVID in young peopleLink provided by the sponsor.
Respiratory syndromeLink provided by the sponsor.
Individual participant dataSharing planned: No

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Simone Ladeia-Andrade, MD PhD principal investigator

Oswaldo Cruz Institute, Oswaldo Cruz Foundation

Igor C Johansen, PhD study chair

University of Campinas, Brazil

Marcelo U Ferreira, MD PhD study chair

University of Sao Paulo

4 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing BCG (Bacillus Calmette-Guérin) vaccine in people with COVID-19, run by Oswaldo Cruz Foundation at 4 sites in Brazil.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 8 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of SARS-Cov-2 infection in both groups over the follow-up (time frame: Up to six months from recruitment day). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05507671, which also lists 41 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Aug 2025; AzTrials last refreshed its copy on 8 Nov 2026.