When the vaccines were being produced to guard against the approaching pandemic Influenza (H1N1), the European Centre of Disease Prevention and Control (ECDC) called on the VAESCO project, coordinated by the Brighton Collaboration for risk assessments. The challenge was to assess the risk of rare adverse events within a very short time frame. We faced this study by bringing together study centers to link databases from multiple European countries.
The activities were closely observed by several European Agencies (EC, EMA, ECDC) and the World Health Organization (WHO). This project proved that international data linkage for vaccine safety assessment was not only feasible but also useful to public health decision makers.
During this pioneering project all centers adhered to a single protocol and utilized Brighton standards wherever available. We customized software that had already been successful in drug safety studies (EU-ADR, SOS) for standardized data transmission and analyses of vaccine safety data.  

This project accomplished the following in the field of vaccine safety research:

• First multinational datal inkage
  
• Largest background incidence study – 250 Mpy
  
• First multinational hypothesis testing study
  
• Largest vaccine safety data linkage effort – 120 Mio
  
• First standardized person level data transfer accross borders
  
• First methodologic double approach : self controlled case series in parallel to case control study
  
• Largest study on the risk of Guillan-Barré Syndrome following pandemic influenza vaccines involvoing over 100 cases

To demonstrate the feasibility of a collaborative, WHO-sponsored consortium of vaccine safety researchers and their respective organizations from developed and middle income countries that can utilize medical hospitalization databases to assess the risk of a medical outcome following vaccination. The association of Guillain-Barré Syndrome and H1N1 influenza vaccination is utilized as a proof of principle.

VAESCO project partners were involved in protocol design and continue to participate in the data analysis group of this project. It is intended to contribute data from the VAESCO project to this global case series.