National and subnational short-term forecasting of COVID-19 in Germany and Poland during early 2021.

Background: During the COVID-19 pandemic there has been a strong interest in forecasts of the short-term development of epidemiological indicators to inform decision makers. In this study we evaluate probabilistic real-time predictions of confirmed cases and deaths from COVID-19 in Germany and Poland for the period from January through April 2021.

Methods: We evaluate probabilistic real-time predictions of confirmed cases and deaths from COVID-19 in Germany and Poland.

[A mathematical model to estimate the number of unreported SARS-CoV-2 infections in the early phase of the pandemic using Germany and Italy as examples].

Background: Especially in the early phase, it is difficult to obtain reliable figures on the spread of a pandemic. The effects of the COVID-19 pandemic and the associated comprehensive but incomplete data monitoring provide a strong reason to estimate the number of unreported cases.

Aim: The aim of this paper is to present a simple mathematical model that allows early estimation of the number of unregistered cases (underreporting).