The striking differences and similarities between the Spanish-flu of 1918 and the Coronavirus disease of 2019 (COVID-19) are analyzed. Progress in medicine and technology and in particular the availability of vaccines has decreased the death probability from about 2% of the affected for the Spanish-flu, to about 10-5 in the UK and 10-3 in Italy, USA, Canada, San Marino and other countries for COVID-19. The logistic map reproduces most features of the disease and may be of guidance for predictions and future steps to be taken in order to contrast the virus. We estimate 6.4 107 deaths worldwide without the vaccines, this value decreases to 2.4 107 with the current vaccination rate. In August 2021, the number of deceased worldwide was 4.4 106. To reduce the fatalities further, it is imperative to increase the vaccination rate worldwide to at least 120 millions/day.
Controlling the worldwide chaotic spreading of COVID-19 through vaccinations