The identification of the severe COVID-19 virus in December 2019 led the World Health Organization to declare a global pandemic by March 2020. Up till recently with the first available vaccines, the only prevention measures include strict social, travel, and working restrictions in a so-called lockdown period that lasted for several weeks (mid-March to the end of April 2020 for most of Europe). This abrupt change in social behavior is expected to impact local but also regional atmospheric composition, and the environmental impact is potentially of high interest to policy and decision-makers.The Aerosol, Clouds, and Trace Gases Research Infrastructure (ACTRIS) is a pan-European research infrastructure producing high-quality data and information on short-lived atmospheric constituents and on the processes leading to the variability of these constituents in natural and controlled atmospheres. Realizing the crucial scientific value of ACTRIS observations of atmospheric composition changes across Europe, the ACTRIS community promptly actioned internal communication thread to organize and set-up COVID-19 related activities.  Such reactive internal involvement of ACTRIS partners generated timely outcomes. In fact, during the lockdown period in spring 2020, most of the ACTRIS observational and exploratory platforms were operational providing continuous access to data on air quality and atmospheric composition and, as a tailored service arrangement, to reinvent ACTRIS simulation chambers for testing mask filtering efficiencies. ACTRIS response to the COVID-19 pandemic showcases multiple benefits to policy- and decision-makers focused on environmental and societal impacts of COVID-19 and the closing down of several sectors of society (e.g. transport, industry, services). To boost the visibility of ACTRIS COVID-19 response at the European level, ACTRIS actively engaged and collaborated with the wider community of Research Infrastructures (ESFRI, ENVRI, and ERF-AISBL) in Europe to support joint activities for SARS-CoV-2.  The Open Science Session on COVID-19 during the ACTRIS week event brought together a broad audience and key-note speaker from major European agencies and organizations (ESA, ECMWF, FMI, ICOS). The online format of the event created the opportunity to open ACTRIS science to a broader public. At the national level, atmospheric scientists were interviewed on COVID impacts raising awareness on the work undertaken in the research infrastructure to the general public.ACTRIS aims at establishing further engagement and direct communication with decision and policy-makers and, for that, envisage the implementation of ad-hoc efforts. This presentation will showcase the various efforts and success stories to capture society as well as policy- and decision-makers.