NCT04747821

Brief 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. 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.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
27,711

participants targeted

Target at P75+ for phase_4 covid19

Timeline
Completed

Started Feb 2021

Longer than P75 for phase_4 covid19

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

February 5, 2021

Completed
2 days until next milestone

Study Start

First participant enrolled

February 7, 2021

Completed
3 days until next milestone

First Posted

Study publicly available on registry

February 10, 2021

Completed
2.1 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 7, 2023

Completed
5 months until next milestone

Study Completion

Last participant's last visit for all outcomes

July 20, 2023

Completed
Last Updated

February 15, 2024

Status Verified

February 1, 2023

Enrollment Period

2.1 years

First QC Date

February 5, 2021

Last Update Submit

February 14, 2024

Conditions

Covid19

Keywords

COVID-19 VaccinesVaccines, Inactivated

Outcome Measures

Primary Outcomes (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

    Thirteen weeks after the beginning of study vaccination

Secondary Outcomes (11)

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

    One year after the beginning of study vaccination

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

    One year after the beginning of study vaccination

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

    One year after the beginning of study vaccination

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

    One year after the beginning of study vaccination

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

    One year after the beginning of study vaccination

  • +6 more secondary outcomes

Other Outcomes (1)

  • Frequency of SARS-CoV-2 variants in the study area

    One year after the beginning of study vaccination

Study Arms (4)

First group of clusters

EXPERIMENTAL

Adsorbed COVID-19 (Inactivated) vaccine offered in the first week of study The vaccine is administrated in two doses with a four-weeks interval

Biological: Adsorbed COVID-19 (Inactivated) Vaccine

Second group of clusters

EXPERIMENTAL

Adsorbed COVID-19 (Inactivated) vaccine offered in the second week of study The vaccine is administrated in two doses with a four-weeks interval

Biological: Adsorbed COVID-19 (Inactivated) Vaccine

Third group of clusters

EXPERIMENTAL

Adsorbed COVID-19 (Inactivated) vaccine offered in the third week of study The vaccine is administrated in two doses with a four-weeks interval

Biological: Adsorbed COVID-19 (Inactivated) Vaccine

Fourth group of clusters

EXPERIMENTAL

Adsorbed COVID-19 (Inactivated) vaccine offered in the fourth week of study The vaccine is administrated in two doses with a four-weeks interval

Biological: Adsorbed COVID-19 (Inactivated) Vaccine

Interventions

Adsorbed COVID-19 (Inactivated) VaccineBIOLOGICAL

Adsorbed COVID-19 (inactivated) Vaccine manufactured by Sinovac

Also known as: CoronaVac
First group of clustersFourth group of clustersSecond group of clustersThird group of clusters

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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.

You may not qualify if:

  • 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;
  • 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;
  • +2 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Hospital Estadual de Serrana

Serrana, São Paulo, 14150-000, Brazil

Location

MeSH Terms

Conditions

COVID-19

Interventions

Vaccinessinovac COVID-19 vaccine

Condition Hierarchy (Ancestors)

Pneumonia, ViralPneumoniaRespiratory Tract InfectionsInfectionsVirus DiseasesCoronavirus InfectionsCoronaviridae InfectionsNidovirales InfectionsRNA Virus InfectionsLung DiseasesRespiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Biological ProductsComplex Mixtures

Study Officials

  • Fernanda Boulos, MD, MSc

    Butantan Institute

    STUDY DIRECTOR

Study Design

Study Type
interventional
Phase
phase 4
Allocation
RANDOMIZED
Masking
NONE
Purpose
PREVENTION
Intervention Model
PARALLEL
Model Details: Groups of cluster are allocated to offer vaccination in a stepped-wedge mode.
Sponsor Type
OTHER GOV
Responsible Party
SPONSOR

Study Record Dates

First Submitted

February 5, 2021

First Posted

February 10, 2021

Study Start

February 7, 2021

Primary Completion

March 7, 2023

Study Completion

July 20, 2023

Last Updated

February 15, 2024

Record last verified: 2023-02

Locations

BR(1)