Vaccine Effectiveness, Burden and Impact Studies (VEBIS) of COVID-19 and Influenza – Tender Specifications OJ/2021/DPR/12924  revision of study documents and the extension of the study and inclusion of  additional study sites.  The pilot study will inform the creation of a master protocol(s) for vaccine  effectiveness/impact studies using health registries. The study design(s) will be  discussed with ECDC considering the most appropriate methodological approach to  address the research objectives and consider the time needed to obtain results. A  study plan presented in the annual work plan of the lot will be submitted to ECDC  for approval, additional aspects and decisions will be taken during the monthly  conference calls.  DL 4.2.3. EU/EEA  master protocol for a  study on vaccine  effectiveness using  health registries  The contractor will produce a protocol for a study on vaccine effectiveness using  health registries, based on lessons learned from the pilot study (DL 4.2.2).  This deliverable includes a statistical analysis plan for a pooled analysis. The protocol will include a codebook with a minimum set and the full list of  variables to be collected; sample size calculations, matching algorithm for data  originating from multiple health register and checking for duplicate data.  The protocol will include standard operating procedures (SOPs) for recruitment of  health care databases, study participants, data management, data checking and  validation, reporting and data transfers, and data analysis, as annexes of the study  protocol.  Four times during  the duration of the  framework  contract Word – ECDC  template  DL 4.2.4. Proposed list  of countries/sites  joining the study  Based on the outcome of the landscape analysis (DL 4.2.1) and a list of countries  initially identified by ECDC, the contractor will identify suitable study sites for  performing the study. The proposed list (DL 4.2.4) will be based on a set of  requirements for country/study sites to be eligible to the study and in particular the  availability of suitable health outcome registries. The identified sites shall be able to  implement the protocol(s).  Three times during  the duration of the  framework  contract, in year 1,  2 and 3  Word  DL 4.2.5. Report  describing all  participating  Descriptive report. Standard template to be used across sites/cohorts.  The report will include full list of participating countries/sites with a named focal  point (“site”-specific study investigator), each health registry to be used, status of  Every two years Word - ECDC  template; Power  point 