Vaccine Effectiveness, Burden and Impact Studies (VEBIS) of COVID-19 and Influenza – Tender Specifications ECDC/2021/12924  The protocol should include: a detailed description of the study design; a study  participants recruitment plan; a list of all study outcomes and variables of  interest; all testing and laboratory components to be included in the study, type  and frequency of sampling; a codebook with a minimum set and the full list of  variables to be collected; sample size calculations; questionnaire/s to be  administered to the study participants; and a statistical analysis plan for a pooled  analysis.  All protocols will need to be designed to ensure compatibility with the TESSy  platform and shall provide schemes/identify data flows to ensure that the  highest proportion of sequencing is performed, through the national schemes or  for example with support from ECDC. DL 1.3.3. ECDC protocol  for influenza vaccine  effectiveness  Development of an influenza vaccine effectiveness protocol, aimed at the  estimation of seasonal influenza vaccine effectiveness in the ECDC Hospital  network, taking into account the status of the SARI surveillance and the COVID- 19 vaccine effectiveness studies and ongoing initiatives of WHO, EC, EMA and  other stakeholders. The protocol should include: a detailed description of the study design; a study  participants recruitment plan; a list of all study outcomes and variables of  interest; all testing and laboratory components to be included in the study,  type and frequency of sampling; a codebook with a minimum set and the full  list of variables to be collected; sample size calculations; questionnaire/s to be  administered to the study participants; and a statistical analysis plan for a  pooled analysis.  All protocols will need to be designed to ensure compatibility with the TESSy  platform and shall provide schemes/identify data flows to ensure that the  highest proportion of sequencing is performed, through the national schemes or  for example with support from ECDC. Once, during the  first specific  contract Word– ECDC  template 