Assessing the influence of climate on wintertime SARS-CoV-2 outbreaks

High susceptibility has limited the role of climate in the SARS-CoV-2 pandemic to date. However, understanding a possible future effect of climate, as susceptibility declines and the northern-hemisphere winter approaches, is an important open question. Here we use an epidemiological model, constrained by observations, to assess the sensitivity of future SARS-CoV-2 disease trajectories to local climate conditions. We find this sensitivity depends on both the susceptibility of the population and the efficacy of non-pharmaceutical interventions (NPIs) in reducing transmission. Assuming high susceptibility, more stringent NPIs may be required to minimize outbreak risk in the winter months. Our results suggest that the strength of NPIs remain the greatest determinant of future pre-vaccination outbreak size. While we find a small role for meteorological forecasts in projecting outbreak severity, reducing uncertainty in epidemiological parameters will likely have a more substantial impact on generating accurate predictions. Spread of SARS-CoV-2 in the early phase of the pandemic has been driven by high population susceptibility, but virus sensitivity to climate may play a role in future outbreaks. Here, the authors simulate SARS-CoV-2 dynamics in winter assuming climate dependence is similar to an endemic coronavirus strain.

Automated summary

The role of climate in the COVID-19 pandemic has been limited due to high susceptibility, but future disease trajectories are dependent on both population susceptibility and the efficacy of non-pharmaceutical interventions. In the upcoming winter months, stricter NPIs may be necessary to minimize outbreak risk.