  The Covid-19 pandemic has caused impressive damages and disruptions in
social, economic, and health systems (among others), and posed unprecedented
challenges to public health and policy/decision-makers concerning the design
and implementation of measures to mitigate its strong negative impacts. The
Portuguese health authorities are currently using some decision analysis-like
techniques to assess the impact of this pandemic and implementing measures for
each county, region, or the whole country. Such decision tools led to some
criticism and many stakeholders asked for novel approaches, in particular those
having in consideration dynamical changes in the pandemic behavior arising,
e.g., from new virus variants or vaccines. A multidisciplinary team formed by
researchers of the Covid-19 Committee of Instituto Superior T\'ecnico at
Universidade de Lisboa (CCIST analysts team) and medical doctors from the
Crisis Office of the Portuguese Medical Association (GCOM experts team)
gathered efforts and worked together in order to propose a new tool to help
politicians and decision-makers in the combat of the pandemic. This paper
presents the main steps and elements, which led to the construction of a
pandemic impact assessment composite indicator, applied to the particular case
of {\sc{Covid-19}} in Portugal. A multiple criteria approach based on an
additive multi-attribute value theory (MAVT) aggregation model was used to
construct the pandemic assessment composite indicator (PACI). The parameters of
the additive model were built through a sociotechnical co-constructive
interactive process between CCIST and GCOM team members. The deck of cards
method was the technical tool adopted to help in building the value functions
and the assessment of the criteria weights.
