COVID-19 pandemic response in the Meuse-Rhine Euroregion: methods, participation and recommendations of a longitudinal cross-border study

Comparative data collection in transborder areas can contribute to informed decision making processes when dealing with borderless health threats such as pandemics, and thus help minimize the negative health effects for its citizens. To examine the pandemic response over time and the impact of infectious disease control in a cross-border setting, a prospective longitudinal study was conducted in the border area between Germany, Belgium and the Netherlands. In the spring of 2021, a random sample of 26,925 adult citizens selected from governmental registries was invited to collect a blood sample at home for SARS-CoV-2 antibody testing and to fill in an online questionnaire on attitudes and behaviour towards infection prevention measures, cross-border mobility, social network and support, COVID-19 self-reported infection(s) and symptoms, vaccination, general self-reported health and socio-demographics. In autumn 2021, participants were invited for a follow-up round. An online tool was developed to coordinate fieldwork procedures, real-time monitoring of participation and consultation of antibody test results. Furthermore, a helpdesk in all three languages for participants’ support was set up.