Vaccine Effectiveness, Burden and Impact Studies (VEBIS)
In the context of the Vaccine Monitoring Platform ECDC implements vaccine effectiveness (VE) studies with a focus on a multi-country approach and sustained infrastructure over time.
Since the end of 2020, ECDC has contracted Epiconcept and a consortium of partners from Ireland (Health Protection Surveillance Centre, HSPC), Portugal (Instituto Nacional de Saúde Doutor Ricardo Jorge, I.P, INSA) and Spain (Instituto de Salud Carlos III, ISCIII) to launch different studies, and from the end of 2021, these were included in the context of the Vaccine Effectiveness, Burden and Impact studies (VEBIS) of COVID-19 and Influenza project. The current studies are:
- Hospital-based multi country study to measure vaccine effectiveness against severe disease (i.e. hospital admission with Severe Acute Respiratory Infection (SARI));
- Cohort-based multi-country study to measure vaccine effectiveness against infection, evaluated in a cohort of healthy individuals (healthcare workers);
- Registries/healthcare database multi country study to measure vaccine effectiveness, evaluated using population-level data;
- Primary care multi-country study to measure vaccine effectiveness against moderate disease (i.e. primary care access).
Network and infrastructure
The current vaccine effectiveness studies within the VEBIS project include over 70 sites in 23 EU/EEA countries.
In order to expand current VE studies through VEBIS and for future vaccine effectivenesss research efforts under the VMP collaboration, opportunities are sought or have been sought over time to expand geographical representation within the European Union/European Economic Area (EU/EEA). Any formal outreach to form or expand a network goes via the Member State National Coordinators, in line with the ECDC Coordinating Competent Bodies model. Furthermore, it is of the utmost importance to ensure that any studies implemented are independent of the pharmaceutical industry.
1. Vaccine effectiveness against severe disease (hospital admission with Severe Acute Respiratory Infection)
The aim of the study related to Severe Acute Respiratory Infection (SARI) is to establish a sustainable ECDC hospital network infrastructure to perform influenza and COVID-19 vaccine effectiveness (VE) studies against severe disease.
Study objectives
The primary objective of this vaccine effectiveness study is to measure the effectiveness of COVID-19 vaccines and influenza vaccines against SARI due to (laboratory-confirmed) SARS-CoV-2 and/or influenza in hospitalised patients. This will be done within each EU/EEA participating country and in a pooled multi-country analysis.
The core VEBIS protocol is updated on a regular basis.
Study period
End of 2020 to present.
Study design
This is a multi-centre, hospital-based, test-negative, case–control study using pooled data from several countries.
Study population
This study is being conducted primarily in countries with pre-existing SARI surveillance systems, to facilitate the recruitment of patients. Therefore, the study population is comprised of individuals of all ages who belong to the target group for vaccination, are hospitalised with SARI symptoms in participating hospitals/services and have no contra-indication for COVID-19 vaccination (for the COVID-19 vaccine effectiveness study) and no contraindication to influenza vaccine (for the influenza vaccine effectiveness study).
Latest outputs
The study protocols and results are continuously published in reports and peer reviewed articles as they become available.
Study protocols
Study results
2. Assessment of COVID-19 and influenza vaccine effectiveness against infection among healthcare workers
The aim of this work is to support the development and implementation of a multicentre European study to estimate COVID-19 and influenza vaccine effectiveness in hospital-based healthcare workers against all laboratory-confirmed SARS-CoV-2 infection (symptomatic and asymptomatic) and laboratory-confirmed influenza infection.
The core protocol is updated on a regular basis. Protocols, ECDC reports and scientific publications related to this study are published on a regular basis.
Study objectives
The primary objective of this study is to measure product-specific COVID-19 VE among hospital healthcare workers eligible for vaccination against laboratory-confirmed SARS-CoV-2 infection.
Study design
Prospective longitudinal multicentre cohort study. Testing will be done according to the table below.
| Timepoint in the study | Questionnaire | Molecular testing | Serology |
|---|---|---|---|
| Enrolment | |||
| Enrolment questionnaire | Nasal, naso- or oropharyngeal swab Saliva specimen | Serum | |
| Follow-up | |||
| Weekly/biweekly | Weekly update | Nasal, naso- or oral-pharyngeal swab or saliva specimen | - |
| Every 4-12 weeks | - | - | Serum |
| Onset of symptoms | Update on symptoms | Nasal, naso- or oral-pharyngeal swab | - |
| Confirmed SARS-CoV-2 infection | Update on symptoms and outcomes | Genetic sequencing of all or a sample of confirmed cases | - |
Study population
Healthcare workers at participating hospital sites, eligible for vaccination, with no contraindication for receiving COVID-19 vaccine.
Lot 2 participating sites and institutes.
Influenza vaccine effectiveness study
During the winter season 2022−2023, a prospective multi-country cohort study was launched to measure the effectiveness of influenza vaccines in hospital-based healthcare workers during a period of influenza and SARS-CoV-2 co-circulation. The protocol is embedded in the COVID-19 VE study in, set up under the VEBIS multi-country cohort study to investigate VE in healthcare workers. The study continued during the 2023−2024 season in hospital-based healthcare workers at the hospital sites included in the main COVID-19 VE study.
The primary objective of this study is two-fold:
- to measure influenza VE against laboratory-confirmed influenza infection among hospital healthcare workers eligible for influenza vaccination;
- to determine the reliability of RT-PCR testing using saliva specimens.
Latest outputs
The study protocols and results are continuously published in reports and peer reviewed articles as they become available.
Study protocols
Study results
3. Vaccine effectiveness and the impact of COVID-19 vaccines through routinely-collected exposure and outcome data using health registries
Throughout the EU/EEA, several countries have digital solutions available for the recording of individual vaccination status. These solutions may allow for an assessment of vaccine effectiveness against respiratory infections caused by SARS-CoV-2, by linking individual vaccination data with relevant health outcome data.
The study relies on routinely-collected vaccination status information and COVID-19 outcome data using pre-established health data registries.
Study objectives
To measure vaccine effectiveness (VE) of COVID-19 vaccines, in community-dwelling resident populations in EU/EEA countries, against the following outcomes:
-
Hospital admission due to COVID-19 with laboratory-confirmed SARS-CoV-2 infection;
-
Death due to COVID-19 with laboratory-confirmed SARS-CoV-2 infection.
Study design
This is a retrospective cohort study, using data collected routinely from electronic health records databases.
Study population
The study population includes people in the national vaccination plan and/or the reference population registries fulfilling the following criteria during the different study periods:
- Residents of EU/EEA countries;
- Belonging to the population with vaccine recommendation in place at time of study period;
- Excluding those living in nursing homes or institutions such as prisons.
Lot 3 participating sites and institutes.
Latest Outputs
The study protocols and results are continuously published in reports and peer reviewed articles as they become available.
Study protocols
Study results
4. Vaccine effectiveness against COVID-19 and seasonal influenza among patients presenting to primary care physicians in the EU/EEA
Primary care systems offer the opportunity to conduct vaccine effectiveness studies. Since 2007, ECDC has commissioned annual influenza vaccine effectiveness studies against seasonal influenza in primary care settings. Since February 2022, leveraging previous efforts and experience, the VEBIS primary care network has conducted studies for the vaccine effectiveness of both seasonal influenza and COVID-19 against moderate disease.
Study objectives
The primary objective is to measure the direct effect (effectiveness) of influenza/COVID-19 vaccines against laboratory-confirmed influenza/SARS-CoV-2 infection for each European primary care site/country and for pooled analyses, across all participating European primary care sites.
Study design
Multicentre test-negative case-control study, using pooled data from several sites/countries. Please refer to the core protocol for further details on the study design.
Study population
The study population consists of community-dwelling individuals who consult a participating study physician with influenza-like illness (ILI) or acute respiratory infection (ARI) symptoms and no contraindication for influenza/COVID-19 vaccination.
Lot 4 Participating sites and institutes.