A Comparative Study on COVID-19 Wave Behavior: The Case of Two Counties

The purpose of this article is to analyze the COVID-19 waves in Russia and Bulgaria using a public dataset for COVID-19 cases. The dataset is provided by Our World in Data. Graphical methods are used to show the current distribution of COVID-19 and to predict its future distribution. Regression analysis is also an applicable method if the Rsquared value is comparatively high. The analyzed data for the tested period (01.01.2021 - 23.03.2021) reveal some interesting facts. Even though of the vaccination program, the indicator "total cases per million" (for Bulgaria) continues to increase. Since we do not have total testing of the whole population in Bulgaria, the results of this study may be ambiguous. Some indicators may show a future increase or decrease in the number of cases per million people. Such indicators may be predictors of the COVID-19 distribution and lag effects. The indicator "Positive rate" shows a different behavior of COVID-19 virus in different countries. Similar research may be conducted for other countries.