The aim of the epidemiological studies of VITAL (WP1) is to investigate the full ID burden in ageing adults in a retrospective and prospective pilot studies that were initiated in project year 3. The studies aim to investigate the (potential) vaccine-preventable disease burden in ageing adults in two pilot regions, namely Denmark and the Valencia Region in Spain.

Based on the different outputs, it was decided by the Consortium to focus the retrospective pilot study on Pneumococcal pneumonia (PP) and Invasive extra-intestinal pathogenic Escherichia coli Disease (IED). In parallel, during the second year of VITAL, WP1 prepared the pilot prospective study which aims to assess the impact of Acute Respiratory Infection (ARI) and bacteremia hospitalization on quality of life, frailty and disability in the ageing population.

During the third year of the VITAL project a research article titled “European data sources for computing burden of (potential) vaccine-preventable diseases in ageing adults” has been published in BMC Infectious Diseases. This article provides an overview of available data sources to calculate the burden of disease of (potential) vaccine-preventable diseases in participating VITAL countries and pinpoints data gaps, based on epidemiological criteria and vaccine availability data sources containing information on following infections were prioritized: Escherichia coli (ExPEC), norovirus, respiratory syncytial virus, Staphylococcus aureus, and pneumococcal pneumonia.

An overview of all data sources identified has also been made available in a searchable online database. This online database is freely accessible using following link: VITAL DATA SOURCES (

For the retrospective study, the statistical analysis plan has been prepared. This plan describes into detail how the data for the retrospective study will be managed and analyzed, and which output will be expected from the analysis. The protocol and statistical analysis plan will be evaluated and adjusted during the pilot phase of the study in the aging population in Denmark and the Valencia region.

During the third year of the project joint meetings between WP1 and WP3 have initiated, both virtual as well as one face-to face meeting. These meetings allow to stay up to date about each other’s activities, provide more insight into each other’s activities and to assure the information output of WP1 is in line with the required input for WP3. Information gaps and how to approach these gaps were discussed. Regular WP1 – WP3 meetings will continue in the next year of the project.

The recruitment of patients and patient follow-up in the prospective study has continued during the third year and fourth year of the project. Adjustments were made to limit the number of COVID cases to be enrolled to avoid overrepresentation of COVID cases and underrepresentation of other infections. Table 1 presents the number of patients enrolled up to June 2022. In total 1284 patients were enrolled, of which 384 ARI cases, 155 bacteremia cases, and 745 control cases. An agreement has been obtained with German centers, adding a fourth country to the project. Administrative steps for signing the contracts are currently being taken. Having a fourth country on board will further increase the rate of enrollment.

Table 1: Number of patients enrolled in the AEQUI study

  • Participating Country
  • France
  • Italy
  • Spain
  • Germany
  • ARI cases
  • 33
  • 169
  • 182
  • 0
  • Bacteremia cases (n)
  • 61
  • 16
  • 78
  • 0
  • Control patients (n)
  • 63
  • 216
  • 466
  • 0
  • Total of inclusions
  • 157
  • 401
  • 726
  • 0
  • Last update received
  • 10 June 2022
  • 9 June 2022
  • 9 June 2022
  • TBD

Both for the Valencia region as for Denmark data extraction has been finalized, after facing an important delay due to competing COVID related activities at the level of both databases. The data of the Valencia region have been processed and analytical tables have been produced and validated. These tables are being used for the analyses. Preliminary results for Valencia will be included in the interim report of the pilot study which will be submitted to IMI by the end of June. Also for Denmark data exploration has started, however these results will become available at a later stage to be included in the final report. Some updates to the protocol and statistical analysis plan have already been discussed, for example the differences in ICD coding practices between Valencia and Denmark. These differences require adjustments to the clinical case definitions for both datasets.