Study identification


EU PAS number


Study ID


Official title and acronym

Real-world effectiveness of different COVID-19 vaccines in Spain: a cohort study based on public electronic health records (BIFAP) (effectiveness of COVID-19 vaccines in Spain)

DARWIN EU® study


Study countries


Study description

Background: The real-world effectiveness of COVID 19 vaccines must be evaluated in populations in Spain. Objectives: To evaluate the effectiveness of all COVID 19 vaccines administered in reducing the medically attended diagnosis of COVID 19 in any setting (confirmed through test and regardless the prognosis and clinical phenotype) Secondary objectives will split the effectiveness -by asymptomatic, symptomatic, Hospitalisations/Intensive care unit (ICU) admissions for COVID 19 and All-cause mortality -by clinical subgroups (old people, patients with cardiovascular disease, diabetes, chronic pulmonary disease, chronic renal impairment, treated cancer, patients with a history of transplantation, Down Syndrome, smoking, males and obesity) -along the time since complete vaccination (3 months, 6 months and ever after). Study design: Observational cohort study to compare the occurrence of covid-19 infection among unvaccinated and vaccinated individuals. Population: Individual with at least 1 year of record with their primary care physician from December 2020 till the last available date at study start. Data sources: Base de datos para la Investigación farmacoepidemiológica en Atención Primaria (BIFAP) and linked registries of 1) COVID positive test results, 2) hospital COVID diagnosis or 3) discharged COVID diagnosis. BIFAP database includes up-to-standard information for more than 9 million patients in Spain. Analysis: Characteristics of the vaccinated and unvaccinated groups at baseline will be described. Incidence rates of COVID 19 outcomes will compared between the two groups, and vaccine effectiveness measures will be estimated by 1 minus the hazard ratios (HR, 95%CI). Period effect estimates (e.g. at 3, 6, or >6 months after vaccination) will be estimated as well as stratified analysis by clinical subgroups and calendar periods. Sensitivity analyses will evaluate the robustness of the approach accross variations of the methodology.

Study status

Research institution and networks


Contact details

Elisa Martín-Merino

Primary lead investigator
Study timelines

Date when funding contract was signed


Study start date


Data analysis start date


Date of final study report

Sources of funding

More details on funding

AEMPS's own resources. No funding has been received.
Study protocol
Initial protocol
English (1.42 MB - PDF)View document

Was the study required by a regulatory body?


Is the study required by a Risk Management Plan (RMP)?

Not applicable