A study proposes that habitat for bats—and their accompanying coronaviruses—has increased in southern Asia over the last century, but experts debate the reliability of the analysis.

The basic reproductive R0, along with the more malleable effective reproduction number Re, are centerpieces of most epidemiological models that are informing government responses to COVID-19.

The SARS-CoV-2 pandemic has revealed the limitations of R0 as no other disease outbreak has before, at a time when policymakers need accurate forecasts.

Modelers try a new approach to gauge the true number of COVID-19 cases in the US by using surveillance data for flu-like illnesses.

Lacking many diagnostic test results from the first major outbreak, researchers have been left to scour other sources for clues about what happened in the early days of the pandemic.

Social distancing measures are based on limited data. As much of the world remains stuck in lockdown, researchers are trying to measure the benefits.