Burden of disease studies derived from the surveillance of Severe Acute Respiratory Infections will also  contribute to the understanding of the impact of respiratory infections in society.  The parallel work performed by ECDC, EMA, World Health Organisation (WHO), the EU National  Immunisation Technical Advisory Groups (NITAG) collaboration, as well as other stakeholders, will also  need to be taken into account when developing the activities described in the tender.  The  scope  of this call is to support the activities of ECDC in the area of surveillance, prevention and control  of respiratory infectious diseases. More specifically the scope of the call is to support the ECDC in  contributing to enhance surveillance systems of severe acute respiratory infections, describe the burden  of respiratory infectious diseases as well as to monitor the impact of interventions such that of vaccination  and the effectiveness of COVID-19 and seasonal influenza vaccines in the field, in order to provide the  evidence for recommendations to strengthen and improve vaccination programmes at the national and  European level.  This will be achieved through enhancing surveillance systems or conducting studies in specific populations  or settings. The overall  objectives  of this call for tender are:  13  2.1.4 Scope and objectives of the call for tender  References:  1. ECDC Founding Regulation (EC) No 851/2004 of the European Parliament and of the Council of 21  April 2004 establishing a European Centre for disease prevention and Control  2. Decision No 1082/2013/EU of the European Parliament and of the Council of 22 October 2013 on  serious cross-border threats to health and repealing Decision No 2119/98/EC 3. Council Recommendation of 7 December 2018 on strengthened cooperation against vaccine- preventable diseases (2018/C 466/01)  4. Commission Implementing Decision (EU) 2018/945 of 22 June 2018 on the communicable diseases  and related special health issues to be covered by epidemiological surveillance as well as relevant  case definitions  5. Communication from the Commission to the European Parliament and the Council of 15 October  2020 on Preparedness for COVID-19 vaccination strategies and vaccine deployment, COM  (2020)680 final • To support ECDC in further developing and maintaining a hospital-based system for Severe Acute  Respiratory Infections which will allow to monitor trends of acute respiratory infections, describe  the impact of interventions and burden of disease (Lot 1)  • To support ECDC in the monitoring of vaccine effectiveness against COVID-19 and seasonal  influenza vaccines through a hospital-based system (Lot 1)  • To support ECDC in the assessment of the impact of vaccination programmes of COVID-19 vaccines  and seasonal influenza (Lot 1) • To support ECDC in the assessment of COVID-19 vaccine effectiveness against COVID-19 among  healthcare workers (Lot 2)  • To support ECDC in assessment of COVID-19 vaccine effectiveness and in special settings such as  in long-term care facilities (Lot 3)  • To support ECDC in establishing community-based vaccine effectiveness and impact studies using  routinely collected exposure and outcome data. (Lot 4) 