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Covid19Phase 4ProjetoSNCT04747821

An Effectiveness Study of the Sinovac's Adsorbed COVID-19 (Inactivated) Vaccine

A Phase 4 study testing Adsorbed COVID-19 (Inactivated) Vaccine in people with Covid19, run by Butantan Institute at 1 site in Brazil.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This is a stepped-wedge cluster randomized trial to assess effectiveness of Sinovac's Adsorbed COVID-19 (Inactivated) vaccine. Residents in the urban area of a municipality are eligible to participate. The city was divided in clusters and those cluster were grouped to determine the offer of vaccination in four steps. Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
Covid19
What is being tested?
Adsorbed COVID-19 (Inactivated) Vaccine
Type of treatment
Vaccines
Could I receive a placebo?
No, everyone receives an active treatment
How many people
27,711 participants
Where
1 siteBrazil
Study dates
7 Feb 2021to 20 Jul 2023
Phase
Phase 4
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

Who may be able to join

  • Adults 18 years of age or older;
  • Resident in the study area;
  • Show voluntary intention to participate in the study, documented by the informed consent form signed by participant.

Who cannot join

  • For females: Pregnancy (confirmed by positive beta-hCG test), breastfeeding or intent to engage in sexual relations with reproductive intent without use of birth control methods in the three months following vaccination;
  • Evidence of uncontrolled neurological, cardiac, pulmonary, hepatic or renal disease, according to anamnesis or physical examination. Significant changes in treatment or hospitalizations due to worsening of the condition in the last three months are indicators of uncontrolled disease;
  • Diseases with impaired immune system including: neoplasms (except basal cell carcinoma), congenital or acquired immunodeficiencies and autoimmune diseases not controlled according to anamnesis or physical examination. Significant changes in treatment or hospitalizations due to worsening of the condition in the last three months are indicators of uncontrolled disease;
  • Behavioral, cognitive or psychiatric disease that, in the opinion of the principal investigator or his or her representative physician, affects the participant's ability to understand and cooperate with all study protocol requirements;
  • Any alcohol or drug abuse over the 12 months prior to enrollment in the study that has caused medical, professional or family problems, indicated by clinical history;
  • History of severe allergic reactions or anaphylaxis to the study vaccine or to components thereof;
Show all 17Show fewer
  • History of asplenia;
  • Participation in another clinical trial with an investigational product in the six months prior to enrollment in the study or planned participation in another clinical trial within the two years following enrollment;
  • Previous participation in a study to evaluate a COVID-19 vaccine or prior exposure to a COVID-19 vaccine;
  • Use of immunosuppressant therapy regimens within the six months prior to enrollment in the study for planned use within the two years following enrollment. Immunosuppressant therapy regimens include: antineoplastic chemotherapy, radiation therapy and immunosuppressants to induce transplant tolerance, among others.
  • Use of immunosuppressive doses of corticosteroids within the three months prior to the enrollment in the study and planned use of immunosuppressive doses of corticoids within the three months following enrollment in the study. Immunosuppressive doses of corticosteroids will be considered the equivalent prednisone 20 mg/day for adults, for longer than one week. Continued use of topical or nasal corticosteroids is not considered an immunosuppressant;
  • Received blood products (transfusions or immunoglobulins) within the three months prior to enrollment in the study, or planned administration of blood products or immunoglobulins within the two years following enrollment in the study;
  • Suspected or confirmed fever within the 72 hours prior to vaccination or axillary temperature greater than 37.8 °C* on the day of vaccination (enrollment may be postponed until participant has gone 72 hours without fever);
  • Possible or confirmed case of COVID-19 on the day of vaccination (vaccination can be postponed until the participant completes 72 hours without symptoms or the diagnosis is ruled out);
  • Received live attenuated virus vaccine or inactivated vaccine within the 28 days or 14 days, respectively, prior to enrollment in the study, or immunization planned within the 28 days after enrollment in the study;
  • History of bleeding disorder (e.g. factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following IM injections or venipuncture
  • Any other condition that, in the opinion of the principal investigator or his/her representative physician, could put the safety/rights of potential participants at risk or prevent them from complying with this protocol.

Trial locations and contacts

1 site in 1 country.

Brazil1 site

  • Hospital Estadual de Serrana

    Serrana, São Paulo, 14150-000

Other trials in Brazil

About this study

Official title: A Stepped-wedge Cluster Randomized Trial to Assess the Effectiveness of the Use of the Adsorbed COVID-19 (Inactivated) Vaccine Manufactured by Sinovac

This is a stepped-wedge cluster randomized trial to assess effectiveness of Sinovac's Adsorbed COVID-19 (Inactivated) vaccine. Residents in the urban area of a municipality are eligible to participate. The city was divided in clusters and those cluster were grouped to determine the offer of vaccination in four steps. The vaccine will be offered to adults (18 years old and above) according to the location of their homes in a cluster. The vaccine schedule is two doses with four-weeks interval. Baseline samples to determine previous immunity will be collected before vaccination.

Cases of COVID-19 reported in the city will be recorded according to the WHO clinical progression scale. Comparison of periods before and after vaccination and relation to immunization coverage will be considered for the assessment of effectiveness in the clusters and groups of clusters.

Conditions
Covid19
Being tested
Adsorbed COVID-19 (Inactivated) Vaccine
Keywords
COVID-19 Vaccines, Vaccines, Inactivated
Medical subject headings
COVID-19

What participants receive

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

  • Adsorbed COVID-19 (Inactivated) VaccineBiological

    Also called CoronaVac

    Adsorbed COVID-19 (inactivated) Vaccine manufactured by Sinovac

Study groups in NCT04747821
Study groupRoleWhat they receive
First group of clustersExperimentalAdsorbed COVID-19 (Inactivated) vaccine offered in the first week of study The vaccine is administrated in two doses with a four-weeks interval
Receives: Biological: Adsorbed COVID-19 (Inactivated) Vaccine
Second group of clustersExperimentalAdsorbed COVID-19 (Inactivated) vaccine offered in the second week of study The vaccine is administrated in two doses with a four-weeks interval
Receives: Biological: Adsorbed COVID-19 (Inactivated) Vaccine
Third group of clustersExperimentalAdsorbed COVID-19 (Inactivated) vaccine offered in the third week of study The vaccine is administrated in two doses with a four-weeks interval
Receives: Biological: Adsorbed COVID-19 (Inactivated) Vaccine
Fourth group of clustersExperimentalAdsorbed COVID-19 (Inactivated) vaccine offered in the fourth week of study The vaccine is administrated in two doses with a four-weeks interval
Receives: Biological: Adsorbed COVID-19 (Inactivated) Vaccine

What is being measured

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

  1. Incidence of COVID-19 cases after two-doses immunization schedule in clusters in the first quarter of study

    Number of virologically-confirmed symptomatic COVID-19 six weeks after beginning of study vaccination up to thirteen weeks

    Measured: Thirteen weeks after the beginning of study vaccination

Secondary outcomes (11)

  1. Incidence of COVID-19 cases after two-doses immunization schedule in clusters up to one year of study

    Number of virologically-confirmed symptomatic COVID-19 six weeks after beginning of study vaccination up to one year

    Measured: One year after the beginning of study vaccination

  2. Incidence of COVID-19 cases after two-doses immunization schedule in clusters according to immunization status

    Number of virologically-confirmed symptomatic COVID-19 six weeks after beginning of study vaccination up to one year according to immunization status

    Measured: One year after the beginning of study vaccination

  3. Incidence of COVID-19 cases after two-doses immunization schedule in clusters according to pre-existing SARS-CoV-2 antibodies

    Number of virologically-confirmed symptomatic COVID-19 six weeks after beginning of study vaccination up to one year according to pre-existing SARS-CoV-2 antibodies

    Measured: One year after the beginning of study vaccination

  4. Incidence of COVID-19 cases after two-doses immunization schedule in clusters according to immunization coverage

    Number of virologically-confirmed symptomatic COVID-19 six weeks after beginning of study vaccination up to one year according to immunization coverage

    Measured: One year after the beginning of study vaccination

  5. Incidence of hospitalization and death due to COVID-19 after two-doses immunization schedule in clusters

    Number of hospitalization and death due to COVID-19 six weeks after beginning of study vaccination up to one year

    Measured: One year after the beginning of study vaccination

  6. Change in average number of reported COVID-19 cases in the study area in comparison to other neighboring cities

    Average number of reported COVID-19 cases in the microregion where the study area is located

    Measured: One year after the beginning of study vaccination

  7. Medically-attended adverse reactions to the study vaccine

    Number of medically-attended adverse reactions to the study vaccine

    Measured: One week after each vaccination

  8. Frequency of severe COVID-19 cases

    Frequency of virologically-confirmed severe COVID-19 cases after receiving, at least, one dose of the vaccine

    Measured: From first vaccination up to one year after first dose

  9. Frequency of adverse events of special interest after immunization

    Frequency of adverse events of special interest after receiving, at least, one dose of the vaccine

    Measured: From first vaccination up to one year after first dose

  10. Acceptability of the study vaccine

    Acceptability rate of the study vaccine in the eligible population of each cluster

    Measured: Two weeks after the beginning of study vaccination of the corresponding cluster

  11. Adherence to vaccination schedule

    Adherence rate to vaccination schedule in the population of each cluster

    Measured: Six weeks after the beginning of study vaccination of the corresponding cluster

Timeline

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

  1. First posted10 Feb 2021
  2. Study start7 Feb 2021
  3. Primary completion7 Mar 2023
  4. Study completion20 Jul 2023

Resources

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 4
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Groups of cluster are allocated to offer vaccination in a stepped-wedge mode.
Masking
None (open label)
Enrolment
27,711 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04747821
Sponsor's protocol ID
COV-04-IB
Acronym
ProjetoS
Status last verified
Feb 2023
First submitted
5 Feb 2021
Last updated
15 Feb 2024
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Publications

  • Borges MC, Palacios R, Conde MTRP, Volpe GJ, Ferreira NN, Garibaldi PMM, Fonseca BAL, Calado RT, Coutinho BM, Gomes BBM, de Lima Dias CFS, de Moraes GR, Haddad SK, de Miranda EJFP, Braga PE, Ragiotto L, Franca JID, de Lima MA, de Oliveira Alves LB, de Camargo Vieira Tenorio J, Sampaio SC, Covas DT, Dos Santos Almeida MAAL, Morandi Junior E, Boulos FC. Indirect protection and long-term effectiveness of inactivated COVID-19 vaccine: a stepped-wedge randomised trial in Serrana, Brazil. Sci Rep. 2026 Feb 19;16(1):9879. doi: 10.1038/s41598-026-37815-1.

    PubMed 41714650

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Adsorbed COVID-19 (Inactivated) Vaccine in people with Covid19, run by Butantan Institute 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 17 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: finished, as of the sponsor's last update on 15 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.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

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

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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 COVID-19 cases after two-doses immunization schedule in clusters in the first quarter of study (time frame: Thirteen weeks after the beginning of study vaccination). 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 NCT04747821, which also lists 1 linked publication.

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 15 Feb 2024.

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