  Combinations of intense non-pharmaceutical interventions ('lockdowns') were
introduced in countries worldwide to reduce SARS-CoV-2 transmission. Many
governments have begun to implement lockdown exit strategies that allow
restrictions to be relaxed while attempting to control the risk of a surge in
cases. Mathematical modelling has played a central role in guiding
interventions, but the challenge of designing optimal exit strategies in the
face of ongoing transmission is unprecedented. Here, we report discussions from
the Isaac Newton Institute 'Models for an exit strategy' workshop (11-15 May
2020). A diverse community of modellers who are providing evidence to
governments worldwide were asked to identify the main questions that, if
answered, will allow for more accurate predictions of the effects of different
exit strategies. Based on these questions, we propose a roadmap to facilitate
the development of reliable models to guide exit strategies. The roadmap
requires a global collaborative effort from the scientific community and
policy-makers, and is made up of three parts: i) improve estimation of key
epidemiological parameters; ii) understand sources of heterogeneity in
populations; iii) focus on requirements for data collection, particularly in
Low-to-Middle-Income countries. This will provide important information for
planning exit strategies that balance socio-economic benefits with public
health.
