The incubation periods, the critical immunisation threshold and some other predictors of SARS-CoV-2 disease for different location and different climate countries

We estimate the incubation period values and other forecasting predictors of SARS-CoV-2 for different countries located in different geographical locations of the earth and each one has a certain climate. The considered countries are the United States, Russia, the United Kingdom, Brazil, Spain, Bahrain, Egypt, Iran, Cyprus, India, France, and the Syrian Arab Republic. For estimating of the forecasting predictors values, we use the SEIR epidemic model and Runge-Kutta simulation method. The estimations are done up to the beginning of 2021 in aforementioned countries based on the collected data in these countries. We find that the incubation period values of SARS-CoV-2 are located between 2.5 days which returns to Bahrain and 10 days which returns to some countries in middle east. Also, we find that the average value of this period is about 6.5 days for the different location countries. Besides, we find that the average values of SARS-CoV-2 critical immunisation threshold, SARS-CoV-2 basic reproduction number and SARS-CoV-2 steady state population are 0.5, 2.3 and 0.5 respectively.