Dear Sir/Madam,  ECDC is planning to award the contract(s) resulting from the above procurement procedure. The procurement  documents consist in the contract notice, this invitation letter, the draft contract(s) and the tender specifications  with their respective annexes. All documents are available at the TED e-Tendering website 1  (see specific link in the  contract notice): https://e-Tendering.ted.europa.eu  Economic operators interested in this contract are invited to submit a tender in one of the official languages of  the European Union.  Tenders must be submitted exclusively via the electronic submission system (e-Submission) available from the  above website 2  and accessible on the Funding and Tenders Opportunities portal (F&T portal) 3 . Tenders submitted  in any other way (e.g. e-mail or by letter) will be disregarded.  In order to submit a tender using e-Submission, economic operators (each member of the group in the case of a  joint tender) will need to register in the European Commission's Participant Register  (http://ec.europa.eu/research/participants/portal/desktop/en/home.html) - an online register of organisations  participating in EU calls for tenders or proposals. On registering each organisation obtains a Participant  Identification Code (PIC, 9-digit number) which acts as its unique identifier in the above register. Instructions on  how to create a PIC can be found on this page: https://webgate.ec.europa.eu/fpfis/wikis/pages/viewpage.action?pageId=308979301.  Economic operators already registered in the Participant Register shall reuse their existing PICs when preparing tenders in e-Submission.  Make sure you submit your tender on time:  you are advised to start completing your tender early. To avoid any  complications with regard to late receipt/non receipt of tenders within the deadline, please ensure that you submit  your tender several hours before the deadline. A tender received after the deadline indicated in the procurement  documents will be rejected. Page  1  of  4 Stockholm, 05/05/2021  Subject:  -  Vaccine Effectiveness, Burden and Impact Studies (VEBIS) of COVID-19 and Influenza  OJ/2021/DPR/12924. • Lot 1. ECDC Hospital network for Vaccine Effectiveness, Burden and Impact Studies and  for Surveillance of Severe Acute Respiratory Infections • Lot 2. Assessment of COVID-19 vaccine effectiveness among healthcare workers  • Lot 3. COVID-19 vaccine-related studies in long-term care facilities • Lot 4. Vaccine effectiveness and impact of COVID-19 vaccines through routinely  collected exposure and outcome data using health registries  • Lot 5. Vaccine effectiveness against COVID-19 and seasonal influenza among patients  presenting to primary care physicians in EU/EEA  1. Submission of tenders  1 Subscription to the call for tender at the above link allows interested economic operators to receive e-mail notifications when new  information or documents are published. Subscription is free of charge and does not involve any commitment to submit a tender. 2  For detailed instructions on how to submit a tender please consult the e-Submission Quick Guide available at:  https://webgate.ec.europa.eu/digit/opsys/esubmission/assets/documents/manual/quickGuide_en.pdf. The supported browsers, file types,  size of attachments and other system requirements can be consulted at: https://webgate.ec.europa.eu/fpfis/wikis/x/f6dqEg. In case of  technical problems, please contact the e-Submission Helpdesk (see contact details in the e-Submission Quick Guide) as soon as possible.   https://ec.europa.eu/info/funding-tenders/opportunities/portal/screen/home 