COVID-19NCT05373420
COVID-19 Vaccination Uptake in Belgium : Sociodemographic and Socioeconomic Disparities
An observational study of COVID-19, run by Sciensano at 1 site in Belgium.
Trial summary
In January 2021, the vaccination campaign against coronavirus disease 2019 (COVID-19) started in Belgium. The vaccination campaign was conducted in several phases, with the first phase targeting priority groups starting in January 2021. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- COVID-19
- What is being tested?
- Education level, Household net income and Gender
- Type of treatment
- Vaccines
- How many people
- 5,341,584 participants
- Where
- 1 siteBelgium
- Study dates
- 28 Dec 2020to 31 Aug 2021
- 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
- No healthy volunteers
- Adult, Older adult
Study population: All individuals of 18 years and over tested for COVID-19 at least once in Belgium before 31 August 2021
Who may be able to join
- Tested at least once in Belgium before 31 August 2021
Who cannot join
- people with a national registry status equivalent to deceased
- people with a national registry status equivalent to migrated
- people with a national registry status equivalent to deregistered
- people with an unknown age
- people with an unknown gender
- people with an unknown region
Trial locations and contacts
1 site in 1 country.
About this study
Official title: COVID-19 Vaccination Uptake in Belgium: Sociodemographic and Socioeconomic Disparities - A Retrospective Cohort Study
In January 2021, the vaccination campaign against coronavirus disease 2019 (COVID-19) started in Belgium. The vaccination campaign was conducted in several phases, with the first phase targeting priority groups starting in January 2021. The second phase began in June 2021 with the invitation of everyone aged 18 years and older before extending access to 12 years and older from summer 2021. Children aged 5-11 were also invited for vaccination from December 2021 onwards.
The presence of a social gradient in COVID-19 infections and subsequent outcomes has been clearly demonstrated. Individuals from lower socioeconomic groups, for example with lower income, lower education level or unemployed are more likely to be infected by the SARS-CoV-2 and to develop severe complications after the infection such as hospitalization, ICU admission or death. Certain sociodemographic characteristics such as male gender, older age, living in crowded households, or belonging to ethnic/racial minorities are also associated with a higher risk of COVID-19 infection and severe outcomes. In addition to disparities in infection, hospitalization and mortality, some studies have also documented a lower COVID-19 vaccination coverage among people from disadvantaged socioeconomic groups during COVID-19 pandemic.
Read more
Despite widespread vaccine promotion efforts and the fact that Belgium has the 7th highest full vaccine coverage in the European Union (89% of people over 18 years old had completed their primary course of vaccination on 08 April 2022), concerns regarding vaccine equity remain. Vaccine uptake depends on a range of factors, including the socio-cultural environment, pre-existing health needs and individual choice. Identifying differences in vaccination between population groups is crucial to assess the effectiveness of the vaccination strategy in Belgium and its relationship to the further spread of COVID-19.
The objective is to identify whether vaccination coverage has been equitable across Belgium and, if not, which groups of individuals are less likely to be covered by the COVID-19 vaccine, with respect to their sociodemographic (SD) and socioeconomic (SE) characteristics.
This study therefore aims to highlight SD and SE disparities in the uptake of the first dose of COVID-19 vaccine in Belgium among people of 18 years and over.
Read the detailed description
- Study design and data sources In this retrospective cohort study, the investigators aimed to unravel SE and SD disparities in the uptake of the first COVID-19 vaccine dose using data from the LINK-VACC project. This project was launched by Sciensano, the institute legally responsible for the surveillance of infectious diseases in Belgium (Royal Decree of 21/03/2018), to perform the post-authorization surveillance of COVID-19 vaccines in Belgium. To that aim, selected variables from multiple existing national health and social sector registries were linked at an individual level using the unique Belgian social security number. The databases were linked within a pseudonymised environment hosted by Healthdata.be of Sciensano. For the present study, four databases were used :
- Vaccinnet+, the Belgian vaccine registry, which contains information on all COVID-19 vaccine doses administrated in Belgium. It includes demographical data of the vaccinated person (sex, age, postal code of residence), as well as data on the vaccinator (type (person or organization) and postal code) and on the administrated vaccine (brand of the vaccine, lot number, date of administration, date of registration).
- The COVID-19 Healthdata database containing data from COVID-19 laboratory tests performed in Belgium (data of sampling and test result).
- The STATBEL database provided by the Belgian Statistical Institute which contains variables related to socioeconomic and sociodemographic characteristics.
- The Common Base Registry for HealthCare Actor (CoBRHA) allowing the identification (by profession and specialty) of people who have been licensed to practice a healthcare profession in Belgium.
- Cohort definition The population of interest includes all individuals of 18 years and older tested for COVID-19 at least once in Belgium until the 31st of August 2021 (which is the date of linkage between STATBEL, Vaccinnet+ and the COVID-19 Healthdata database) for whom SD and SE information from STATBEL database was available. The cohort is built from Vaccinnet+ and the COVID-19 Healthdata database which includes all doses of vaccines administered and PCR and rapid antigenic tests performed in Belgium, respectively. As of 31 August 2021, 10 475 908 individuals had been tested and/or vaccinated at least once in Belgium according to Vaccinnet+ and the COVID-19 Healthdata database. On January 1, 2021, the official Belgian population included 11 521 238 inhabitants, demonstrating a high coverage of the total Belgian population by these two data sources (90.92%). The relevant SE and SD variables were then included after linking with STATBEL database based on the individual national identification number. The data source available from STATBEL contains SE and SD information for 10 309 300/10 475 908 individuals registered at least once either in Vaccinnet+ from 28 December 2020 to 31 August 2021 or in the COVID-19 Healthdata database before 31 August 2021, corresponding to a linkage rate of 98.41%. Information on the healthcare license available in CoBRHA were then added. After these linkages, people who were deregistered, migrated and deceased based on their status in the national registry were excluded. People whose age, region or gender were unknown were also excluded. In order to be able to compare vaccination rate according to each SE and SD indicators, the investigators included only individuals tested before 31 August 2021 since it is the date of linkage between Vaccinnet+, COVID-19 Healthdata database and STATBEL. Finally, individuals under 18 years of age were excluded as they were considered as a group in their own right in the vaccination strategy by being vaccinated the latest in a separate phase of the vaccination campaign. The final cohort for this study is therefore composed of 5 341 584 individuals of 18 years and over tested in Belgium until the 31st of August 2021.
- Outcome The outcome variable, provided by Vaccinnet+, is the uptake of the first dose of COVID-19 vaccine until the 31st of August 2021. The investigators considered that, at this date, all individuals over 18 years of age had received an invitation to be vaccinated with the first dose and had the opportunity to receive this dose of vaccine in Belgium.
- Conditions
- COVID-19
- Being tested
- Education level, Household net income, Gender, Migration background, Household type
- Keywords
- COVID-19, Vaccination, socioeconomic factors, sociodemographic factors, Inequity
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Education levelOther
Educational level was classified using the International Standard Classification of Education (ISCED) : ISCED0 (less than primary education), ISCED1 (primary education), ISCED2 (lower secondary school), ISCED3 (upper secondary school), ISCED4 (post-secondary non tertiary education), ISCED5 (short-cycle tertiary education), ISCED6 (bachelor's or equivalent level), ISCED7 (master's or equivalent level), ISCED8 (doctoral or equivalent level). We merged these different categories into three main education level : low (ISCED0 to ISCED2), middle (ISCED3 to ISCED4) and high (ISCED5 to ISCED 8). This information is provided by STATBEL.
Household net incomeOther
Income information is available as deciles of the net income of the whole household. This indicator is further categorized into low income (deciles 1 to 4), middle income (deciles 5 to 7), and high income (deciles 8 to 10). This information is provided by STATBEL.
GenderOther
Male or female. This variable is obtained from the Belgian national registry.
Migration backgroundOther
Migration background is based on the first nationality and the parents' country of origin. This variable distinguishes between native-born individuals, second-generation migrants, first-generation European migrants, and first-generation non-European migrants. This information is provided by STATBEL.
Household typeOther
Household type provides a partial picture of the social environment and is distinguished between one person, couples, couples with children, single parents, other, collectivity (prison, nursing homes, religious community, etc.). This information is provided by STATBEL.
Health literacyOther
Having a health care degree is used as a proxy for health literacy and is provided by CoBRHA. The scientific and medical background can lead to more preventive and responsible behaviors towards infectious diseases. Moreover, being a health professional can lead to the need to protect patients and themselves against infections, without necessarily having very advanced knowledge of infectious diseases and vaccines.
| Study group | Role | What they receive |
|---|---|---|
| All individuals tested for COVID-19 in Belgium | All individuals of 18 years old and over tested for COVID-19 at least once in Belgium until the 31st of August 2021 Receives: Other: Education level; Other: Household net income; Other: Gender; Other: Migration background; Other: Household type; Other: Health literacy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants who received the first dose of COVID-19 vaccine
Uptake of the first COVID-19 vaccine dose until the 31st of August 2021 in Belgium
Measured: 28 December 2020 - 31 August 2021
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 May 2022
- Study start28 Dec 2020
- Primary completion31 Aug 2021
- Study completion31 Aug 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 5,341,584 participants (actual)
Sponsor and investigators
- Lead sponsor
- Sciensano
- Sponsor type
- Other government
- Responsible party
- Sponsor
- Investigators
- Lucy LC Catteau, PhD, Principal investigator, Sciensano
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05373420
- Sponsor's protocol ID
- B.U.N. 1432020000371
- Status last verified
- Mar 2022
- First submitted
- 12 May 2022
- Last updated
- 3 Jun 2022
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Jun 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- COVID-19 Vaccination Uptake in Belgium: Sociodemographic and Socioeconomic Disparities - A Retrospective Cohort Study
- ClinicalTrials.gov ID
- NCT05373420
- Acronym / sponsor ID
- B.U.N. 1432020000371
- Conditions
- COVID-19
- Keywords
- COVID-19, Vaccination, socioeconomic factors, sociodemographic factors, Inequity
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 5,341,584 participants (actual)
- Lead sponsor
- SciensanoOther government
- Study start
- 28 Dec 2020 (actual)
- Primary completion
- 31 Aug 2021 (actual)
- Study completion
- 31 Aug 2021 (actual)
- First posted
- 13 May 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.
In January 2021, the vaccination campaign against coronavirus disease 2019 (COVID-19) started in Belgium. The vaccination campaign was conducted in several phases, with the first phase targeting priority groups starting in January 2021. The second phase began in June 2021 with the invitation of everyone aged 18 years and older before extending access to 12 years and older from summer 2021. Children aged 5-11 were also invited for vaccination from December 2021 onwards.
The presence of a social gradient in COVID-19 infections and subsequent outcomes has been clearly demonstrated. Individuals from lower socioeconomic groups, for example with lower income, lower education level or unemployed are more likely to be infected by the SARS-CoV-2 and to develop severe complications after the infection such as hospitalization, ICU admission or death. Certain sociodemographic characteristics such as male gender, older age, living in crowded households, or belonging to ethnic/racial minorities are also associated with a higher risk of COVID-19 infection and severe outcomes. In addition to disparities in infection, hospitalization and mortality, some studies have also documented a lower COVID-19 vaccination coverage among people from disadvantaged socioeconomic groups during COVID-19 pandemic.
Despite widespread vaccine promotion efforts and the fact that Belgium has the 7th highest full vaccine coverage in the European Union (89% of people over 18 years old had completed their primary course of vaccination on 08 April 2022), concerns regarding vaccine equity remain. Vaccine uptake depends on a range of factors, including the socio-cultural environment, pre-existing health needs and individual choice. Identifying differences in vaccination between population groups is crucial to assess the effectiveness of the vaccination strategy in Belgium and its relationship to the further spread of COVID-19.
The objective is to identify whether vaccination coverage has been equitable across Belgium and, if not, which groups of individuals are less likely to be covered by the COVID-19 vaccine, with respect to their sociodemographic (SD) and socioeconomic (SE) characteristics.
This study therefore aims to highlight SD and SE disparities in the uptake of the first dose of COVID-19 vaccine in Belgium among people of 18 years and over.
Detailed description
- Study design and data sources In this retrospective cohort study, the investigators aimed to unravel SE and SD disparities in the uptake of the first COVID-19 vaccine dose using data from the LINK-VACC project. This project was launched by Sciensano, the institute legally responsible for the surveillance of infectious diseases in Belgium (Royal Decree of 21/03/2018), to perform the post-authorization surveillance of COVID-19 vaccines in Belgium. To that aim, selected variables from multiple existing national health and social sector registries were linked at an individual level using the unique Belgian social security number. The databases were linked within a pseudonymised environment hosted by Healthdata.be of Sciensano. For the present study, four databases were used :
- Vaccinnet+, the Belgian vaccine registry, which contains information on all COVID-19 vaccine doses administrated in Belgium. It includes demographical data of the vaccinated person (sex, age, postal code of residence), as well as data on the vaccinator (type (person or organization) and postal code) and on the administrated vaccine (brand of the vaccine, lot number, date of administration, date of registration).
- The COVID-19 Healthdata database containing data from COVID-19 laboratory tests performed in Belgium (data of sampling and test result).
- The STATBEL database provided by the Belgian Statistical Institute which contains variables related to socioeconomic and sociodemographic characteristics.
- The Common Base Registry for HealthCare Actor (CoBRHA) allowing the identification (by profession and specialty) of people who have been licensed to practice a healthcare profession in Belgium.
- Cohort definition The population of interest includes all individuals of 18 years and older tested for COVID-19 at least once in Belgium until the 31st of August 2021 (which is the date of linkage between STATBEL, Vaccinnet+ and the COVID-19 Healthdata database) for whom SD and SE information from STATBEL database was available. The cohort is built from Vaccinnet+ and the COVID-19 Healthdata database which includes all doses of vaccines administered and PCR and rapid antigenic tests performed in Belgium, respectively. As of 31 August 2021, 10 475 908 individuals had been tested and/or vaccinated at least once in Belgium according to Vaccinnet+ and the COVID-19 Healthdata database. On January 1, 2021, the official Belgian population included 11 521 238 inhabitants, demonstrating a high coverage of the total Belgian population by these two data sources (90.92%). The relevant SE and SD variables were then included after linking with STATBEL database based on the individual national identification number. The data source available from STATBEL contains SE and SD information for 10 309 300/10 475 908 individuals registered at least once either in Vaccinnet+ from 28 December 2020 to 31 August 2021 or in the COVID-19 Healthdata database before 31 August 2021, corresponding to a linkage rate of 98.41%. Information on the healthcare license available in CoBRHA were then added. After these linkages, people who were deregistered, migrated and deceased based on their status in the national registry were excluded. People whose age, region or gender were unknown were also excluded. In order to be able to compare vaccination rate according to each SE and SD indicators, the investigators included only individuals tested before 31 August 2021 since it is the date of linkage between Vaccinnet+, COVID-19 Healthdata database and STATBEL. Finally, individuals under 18 years of age were excluded as they were considered as a group in their own right in the vaccination strategy by being vaccinated the latest in a separate phase of the vaccination campaign. The final cohort for this study is therefore composed of 5 341 584 individuals of 18 years and over tested in Belgium until the 31st of August 2021.
- Outcome The outcome variable, provided by Vaccinnet+, is the uptake of the first dose of COVID-19 vaccine until the 31st of August 2021. The investigators considered that, at this date, all individuals over 18 years of age had received an invitation to be vaccinated with the first dose and had the opportunity to receive this dose of vaccine in Belgium.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| All individuals tested for COVID-19 in Belgium | – | Other: Education level, Other: Household net income, Other: Gender, Other: Migration background, Other: Household type, Other: Health literacyAll individuals of 18 years old and over tested for COVID-19 at least once in Belgium until the 31st of August 2021 |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- All individuals of 18 years and over tested for COVID-19 at least once in Belgium before 31 August 2021
Key inclusion criteria (1 listed)
- Tested at least once in Belgium before 31 August 2021
Key exclusion criteria (6 listed)
- people with a national registry status equivalent to deceased
- people with a national registry status equivalent to migrated
- people with a national registry status equivalent to deregistered
- people with an unknown age
- people with an unknown gender
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 |
|---|---|---|
| Education levelEducational level was classified using the International Standard Classification of Education (ISCED) : ISCED0 (less than primary education), ISCED1 (primary education), ISCED2 (lower secondary school), ISCED3 (upper secondary school), ISCED4 (post-secondary non tertiary education), ISCED5 (short-cycle tertiary education), ISCED6 (bachelor's or equivalent level), ISCED7 (master's or equivalent level), ISCED8 (doctoral or equivalent level). We merged these different categories into three main education level : low (ISCED0 to ISCED2), middle (ISCED3 to ISCED4) and high (ISCED5 to ISCED 8). This information is provided by STATBEL. | Other | All individuals tested for COVID-19 in Belgium |
| Household net incomeIncome information is available as deciles of the net income of the whole household. This indicator is further categorized into low income (deciles 1 to 4), middle income (deciles 5 to 7), and high income (deciles 8 to 10). This information is provided by STATBEL. | Other | All individuals tested for COVID-19 in Belgium |
| GenderMale or female. This variable is obtained from the Belgian national registry. | Other | All individuals tested for COVID-19 in Belgium |
| Migration backgroundMigration background is based on the first nationality and the parents' country of origin. This variable distinguishes between native-born individuals, second-generation migrants, first-generation European migrants, and first-generation non-European migrants. This information is provided by STATBEL. | Other | All individuals tested for COVID-19 in Belgium |
| Household typeHousehold type provides a partial picture of the social environment and is distinguished between one person, couples, couples with children, single parents, other, collectivity (prison, nursing homes, religious community, etc.). This information is provided by STATBEL. | Other | All individuals tested for COVID-19 in Belgium |
| Health literacyHaving a health care degree is used as a proxy for health literacy and is provided by CoBRHA. The scientific and medical background can lead to more preventive and responsible behaviors towards infectious diseases. Moreover, being a health professional can lead to the need to protect patients and themselves against infections, without necessarily having very advanced knowledge of infectious diseases and vaccines. | Other | All individuals tested for COVID-19 in Belgium |
Primary outcome
Number of participants who received the first dose of COVID-19 vaccine
Time frame: 28 December 2020 - 31 August 2021
Uptake of the first COVID-19 vaccine dose until the 31st of August 2021 in Belgium
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Jun 2022.
- Vaccination \| Coronavirus COVID-19Link provided by the sponsor.
- COUVERTURE VACCINALE ET IMPACT ÉPIDÉMIOLOGIQUE DE LA CAMPAGNE DE VACCINATION COVID-19 EN BELGIQUELink provided by the sponsor.
- Association of race, ethnicity, and community-level factors with COVID-19 cases and deaths across U.S. countiesLink provided by the sponsor.
- Community-Level Factors Associated With Racial And Ethnic Disparities In COVID-19 Rates In MassachusettsLink provided by the sponsor.
- Social Determinants of COVID-19 in Massachusetts, United States: An Ecological StudyLink provided by the sponsor.
- Derivation and Validation of Clinical Prediction Rules for COVID-19 Mortality in Ontario, CanadaLink provided by the sponsor.
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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.
Lucy LC Catteau, PhD principal investigator
Sciensano
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, run by Sciensano at 1 site in Belgium.
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 1 inclusion and 6 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 3 Jun 2022. 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 Belgium. 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?
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?
Number of participants who received the first dose of COVID-19 vaccine (time frame: 28 December 2020 - 31 August 2021). 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 3 Jun 2022.