The first casualty of an epidemic is evidence.
The COVID-19 has posed a wide range of urgent questions: about the
disease, testing, immunity, treatments, and outcomes. Extreme
situations, such as pandemics, call for exceptional measures. However,
this threatens the production and application of evidence. This paper
directs evidence production towards four types of uncertainty in order
to address the challenges of the pandemic: Risk, Fundamental
uncertainty, Ignorance, and Ambiguity. Eliminating ambiguity, being
alert to the unknown, and gathering data to estimate risks are crucial
to preserve evidence and save lives. Hence, in order to avoid fake facts
and to provide sustainable solutions we need to pay attention to the
various kinds of uncertainty. Producing high quality evidence is the
solution, not the problem.