COVID-19 VaccinesNCT05621928
Effectiveness of Vaccination Against COVID-19 in Brazil: Case-Control Study
An observational study of COVID-19 Vaccines, run by The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz) at 1 site in Brazil.
Trial summary
The main objective of the study is to evaluate the effectiveness of the vaccine against covid-19, recommended by the national immunization program. This is a multicentric, observational, case-control study. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- COVID-19 Vaccines
- Type of treatment
- Vaccines
- How many people
- 3,920 participants
- Where
- 1 siteBrazil
- Study dates
- 7 Feb 2022to 30 Dec 2024
- How long will I take part?
- 12 Months
- Phase
- Observational
- Are there results?
- None posted in the registry
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
Study population: Participants virologically confirmed incident cases of COVID-19 and Control Participants without COVID-19 (no suspected symptomatology and RT-PCR negative for SARS-CoV in two consecutive naso/oropharyngeal swab samples).
Who may be able to join
- Agreement to participate in the study after reading, understanding and signing the informed consent.
- Availability and possibility of being followed up during the follow-up period defined in the study, through visits to research centers, home visits, telephone contacts or other means of digital communication.
- Completing the case or control definitions described below.
Who cannot join
- Behavioral, cognitive or psychiatric illness that, in the opinion of the responsible investigator or his/her medical representative, affects the participant's ability to understand and comply with the requirements of the study protocol;
- Any other condition that, in the opinion of the responsible investigator or his/her medical representative, may jeopardize the safety or rights of a potential participant or prevent him/her from complying with this protocol.
Trial locations and contacts
1 site in 1 country.
Brazil1 site
Institute of Technology in Immunobiology Bio-Manguinhos/Fiocruz
Rio de Janeiro, 21040-900
About this study
The main objective of the study is to evaluate the effectiveness of the vaccine against covid-19, recommended by the national immunization program. This is a multicentric, observational, case-control study. Participants Cases with the disease will be compared to Control Participants, that is, without the disease, regarding the vaccination history for Covid-19.Complementarily, an evaluation of cellular and humoral immunity will be carried out in a sample of both case and control participants, taking into account the vaccination history.
Read the detailed description
The Covid-19 vaccines currently distributed by the National Immunization Program (NIP) have undergone a rigorous safety and efficacy assessment by the National Surveillance Agency Sanitary prior to the authorization of use in the country. The main objective of vaccination against Covid19 is to reduce its morbidity and mortality and, in the future, to promote the control of transmission from the prevention of symptomatic cases in the general population.
To achieve this goal, however, it is important that the vaccines are administered correctly (according to the vaccination schedule correct application techniques and appropriate storage conditions, for example), in the selected population groups (according to prioritization criteria), with vaccination coverage and selected population groups (according to prioritization criteria), with vaccination coverage and vaccination speeds sufficient for effective control of the disease.That is, there are factors that extrapolate the issues of quality, efficacy and safety evaluated in the pre-registration stages, which are extremely important for the success of immunization programs. Thus, the monitoring of these parameters after large-scale use is essential to ratify the favorable risk-benefit assessment made at the time of decision on the introduction of these vaccines in the NIP.
Regarding the role of vaccines in the prevention and control of target diseases, in addition to data from efficacy and immunogenicity obtained in the controlled situations of clinical trials, it is necessary to extend this assessment to routine situations, i.e., "real life", based on the so-called effectiveness studies. Factors such as storage and administration conditions of these products, issues related to vaccinated populations and individuals may affect the response to vaccines.
Therefore, the monitoring of effectiveness must be continuous, seeking to prove the impact of the vaccines in reducing the occurrence of the disease, as well as generating vaccine immunogenicity data, which can be used in the future as protective inferences in complementary analyses.
Thus, the present research project is a study of the effectiveness of the vaccination whereas the efficacy of licensed vaccines, demonstrated in controlled studies, that needs to be verified in the routine of immunization services throughout the country, with its diversity including different vaccination coverage and circulation of SARS-CoV-2 variants, as well as individual factors, such as age group and presence of comorbidities.
The performance of immunization in susceptible population generates groups exposed and not exposed to the COVID-19 vaccine.
Underlying hypothetical cohorts of vaccinated and unvaccinated cannot be clearly enumerated, and the strategy is to reconstruct the experience of exposure (vaccination) and disease (COVID-19) in this population.
In addition to efficacy data obtained from pre-licensing/authorisation clinical trials and the monitoring of vaccine effectiveness, the main objective of this study, to obtain data on the development of immune response to symptomatic SARS-CoV-2 infection (COVID-19) is of great importance for future immunization actions, especially, the development of future vaccines. In the near future, with the increasing availability of vaccines COVID-19, it will become increasingly difficult (for ethical and programmatic reasons) to conduct trials placebo-controlled clinical trials, which may be replaced by immunogenicity studies.
However, for this, it will be necessary to improve knowledge in relation to the post-infection immune response and also that triggered by vaccination, moving towards the definition of the so-called correlates of serum protection.
In this context, we included in the present case-control study proposal, the establishment of a cohort of cases and controls, grouped according to vaccination history for COVID-19, for follow-up and evaluation of your humoral and cellular immune response.
We understand be an opportunity, based on the identification of virologically confirmed cases and a control with SARS-CoV-2 infection known to be ruled out, observe and describe the humoral and cellular immune response components in these research participants, including duration immunity for a period of 12 months.
- Conditions
- COVID-19 Vaccines
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| cases with positive RT PCR result for Covid 19 | Individuals aged 18 years or older, with a suspected clinical picture of COVID-19 virologically confirmed, that is, with positive RT-PCR for SARS-CoV-2 in a respiratory secretion sample collected in the first 7 days of the onset of symptoms , who did not have a positive RT-PCR result for SARS-CoV-2 in the 90 days preceding enrollment in the study. | |
| Control | Individuals residing in the vicinity of the case, aged 18 years or older, without a suspected clinical picture of COVID-19 and with RT-PCR negative for SARS-CoV-2 in a respiratory secretion sample collected at the time of inclusion, followed by confirmation of the absence of signs and symptoms suggestive of COVID-19 within the next 7 days. | |
| immunogenicity analyzes | a convenience sample composed of all cases exposed or not to vaccination and 200 controls, 100 vaccinated and 100 unvaccinated, for analysis of humoral response. | |
| assessment of cellular immunity | a sample of 100 vaccinated cases and 100 unvaccinated cases followed prospectively, and 100 vaccinated controls 100 unvaccinated controls assessed spot-on at enrollment. | |
| analysis of potential genetic risk factors for the occurrence of severe forms of COVID-19 (SRAG) | a total of 50 cases |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evaluate the effectiveness of the vaccination against COVID-19.
Confirmed disease (RT-PCR positive for SARS-CoV-2), according to:the clinical spectrum (of mild disease , moderate to severe) and outcome (disease-related death);according to the vaccine used, the number of doses and the interval rom the last dose to the onset of symptom;according to the presence of comorbidities and medication use; according to Region/State;according to vaccination coverage;according to circulating viral variants.
Measured: 12 months
Secondary outcomes (2)
Assess the humoral and cellular immune response
in vaccinated or unvaccinated cases compared to vaccinated or unvaccinated controls.
Measured: 15 months
Analyze individual factors
including those related to the adaptive immune response (HLA molecules) and genetic aspects, in severe cases/deaths associated with vaccine failures.
Measured: 15 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Nov 2022
- Study start7 Feb 2022
- Primary completion31 Oct 2023
- Study completion30 Dec 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for COVID-19 VaccinesStudies 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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 3,920 participants (estimated)
- Target duration
- 12 Months
Sponsor and investigators
- Lead sponsor
- The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz)
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05621928
- Sponsor's protocol ID
- 003/2021
- Status last verified
- Feb 2024
- First submitted
- 17 Nov 2022
- Last updated
- 7 Feb 2024
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Feb 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effectiveness of Vaccination Against COVID-19 in Brazil: Case-Control Study
- ClinicalTrials.gov ID
- NCT05621928
- Acronym / sponsor ID
- 003/2021
- Conditions
- COVID-19 Vaccines
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 3,920 participants (estimated)
- Lead sponsor
- The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz)University, hospital or other
- Study start
- 7 Feb 2022 (actual)
- Primary completion
- 31 Oct 2023 (actual)
- Study completion
- 30 Dec 2024 (estimated)
- First posted
- 18 Nov 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.
The main objective of the study is to evaluate the effectiveness of the vaccine against covid-19, recommended by the national immunization program. This is a multicentric, observational, case-control study. Participants Cases with the disease will be compared to Control Participants, that is, without the disease, regarding the vaccination history for Covid-19.Complementarily, an evaluation of cellular and humoral immunity will be carried out in a sample of both case and control participants, taking into account the vaccination history.
Detailed description
The Covid-19 vaccines currently distributed by the National Immunization Program (NIP) have undergone a rigorous safety and efficacy assessment by the National Surveillance Agency Sanitary prior to the authorization of use in the country. The main objective of vaccination against Covid19 is to reduce its morbidity and mortality and, in the future, to promote the control of transmission from the prevention of symptomatic cases in the general population.
To achieve this goal, however, it is important that the vaccines are administered correctly (according to the vaccination schedule correct application techniques and appropriate storage conditions, for example), in the selected population groups (according to prioritization criteria), with vaccination coverage and selected population groups (according to prioritization criteria), with vaccination coverage and vaccination speeds sufficient for effective control of the disease.That is, there are factors that extrapolate the issues of quality, efficacy and safety evaluated in the pre-registration stages, which are extremely important for the success of immunization programs. Thus, the monitoring of these parameters after large-scale use is essential to ratify the favorable risk-benefit assessment made at the time of decision on the introduction of these vaccines in the NIP.
Regarding the role of vaccines in the prevention and control of target diseases, in addition to data from efficacy and immunogenicity obtained in the controlled situations of clinical trials, it is necessary to extend this assessment to routine situations, i.e., "real life", based on the so-called effectiveness studies. Factors such as storage and administration conditions of these products, issues related to vaccinated populations and individuals may affect the response to vaccines.
Therefore, the monitoring of effectiveness must be continuous, seeking to prove the impact of the vaccines in reducing the occurrence of the disease, as well as generating vaccine immunogenicity data, which can be used in the future as protective inferences in complementary analyses.
Thus, the present research project is a study of the effectiveness of the vaccination whereas the efficacy of licensed vaccines, demonstrated in controlled studies, that needs to be verified in the routine of immunization services throughout the country, with its diversity including different vaccination coverage and circulation of SARS-CoV-2 variants, as well as individual factors, such as age group and presence of comorbidities.
The performance of immunization in susceptible population generates groups exposed and not exposed to the COVID-19 vaccine.
Underlying hypothetical cohorts of vaccinated and unvaccinated cannot be clearly enumerated, and the strategy is to reconstruct the experience of exposure (vaccination) and disease (COVID-19) in this population.
In addition to efficacy data obtained from pre-licensing/authorisation clinical trials and the monitoring of vaccine effectiveness, the main objective of this study, to obtain data on the development of immune response to symptomatic SARS-CoV-2 infection (COVID-19) is of great importance for future immunization actions, especially, the development of future vaccines. In the near future, with the increasing availability of vaccines COVID-19, it will become increasingly difficult (for ethical and programmatic reasons) to conduct trials placebo-controlled clinical trials, which may be replaced by immunogenicity studies.
However, for this, it will be necessary to improve knowledge in relation to the post-infection immune response and also that triggered by vaccination, moving towards the definition of the so-called correlates of serum protection.
In this context, we included in the present case-control study proposal, the establishment of a cohort of cases and controls, grouped according to vaccination history for COVID-19, for follow-up and evaluation of your humoral and cellular immune response.
We understand be an opportunity, based on the identification of virologically confirmed cases and a control with SARS-CoV-2 infection known to be ruled out, observe and describe the humoral and cellular immune response components in these research participants, including duration immunity for a period of 12 months.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Target follow-up
- 12 Months
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| cases with positive RT PCR result for Covid 19 | – | –Individuals aged 18 years or older, with a suspected clinical picture of COVID-19 virologically confirmed, that is, with positive RT-PCR for SARS-CoV-2 in a respiratory secretion sample collected in the first 7 days of the onset of symptoms , who did not have a positive RT-PCR result for SARS-CoV-2 in the 90 days preceding enrollment in the study. |
| Control | – | –Individuals residing in the vicinity of the case, aged 18 years or older, without a suspected clinical picture of COVID-19 and with RT-PCR negative for SARS-CoV-2 in a respiratory secretion sample collected at the time of inclusion, followed by confirmation of the absence of signs and symptoms suggestive of COVID-19 within the next 7 days. |
| immunogenicity analyzes | – | –a convenience sample composed of all cases exposed or not to vaccination and 200 controls, 100 vaccinated and 100 unvaccinated, for analysis of humoral response. |
| assessment of cellular immunity | – | –a sample of 100 vaccinated cases and 100 unvaccinated cases followed prospectively, and 100 vaccinated controls 100 unvaccinated controls assessed spot-on at enrollment. |
| analysis of potential genetic risk factors for the occurrence of severe forms of COVID-19 (SRAG) | – | –a total of 50 cases |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Participants virologically confirmed incident cases of COVID-19 and Control Participants without COVID-19 (no suspected symptomatology and RT-PCR negative for SARS-CoV in two consecutive naso/oropharyngeal swab samples).
Key inclusion criteria (3 listed)
- Agreement to participate in the study after reading, understanding and signing the informed consent.
- Availability and possibility of being followed up during the follow-up period defined in the study, through visits to research centers, home visits, telephone contacts or other means of digital communication.
- Completing the case or control definitions described below.
Key exclusion criteria (2 listed)
- Behavioral, cognitive or psychiatric illness that, in the opinion of the responsible investigator or his/her medical representative, affects the participant's ability to understand and comply with the requirements of the study protocol;
- Any other condition that, in the opinion of the responsible investigator or his/her medical representative, may jeopardize the safety or rights of a potential participant or prevent him/her from complying with this protocol.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Evaluate the effectiveness of the vaccination against COVID-19.
Time frame: 12 months
Confirmed disease (RT-PCR positive for SARS-CoV-2), according to:the clinical spectrum (of mild disease , moderate to severe) and outcome (disease-related death);according to the vaccine used, the number of doses and the interval rom the last dose to the onset of symptom;according to the presence of comorbidities and medication use; according to Region/State;according to vaccination coverage;according to circulating viral variants.
2 secondary outcomes
Assess the humoral and cellular immune response
Time frame: 15 months
Analyze individual factors
Time frame: 15 months
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Feb 2024.
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of COVID-19 Vaccines, run by The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz) at 1 site 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 2 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: status not confirmed, as of the sponsor's last update on 7 Feb 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
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?
Evaluate the effectiveness of the vaccination against COVID-19. (time frame: 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 7 Feb 2024.