2 8 Acute respiratory distress syndrome (ARDS) can develop in both cases. While those with the influenza died of secondary bacterial pneumonia, those with COVID-19 died from an overactive immune response that resulted in multiple organ failure. Second, the two diseases kill via different mechanisms.

2 5 In the USA alone, COVID-19 cases are at over 11 million as of 16 November 2020, which is nearly a 40% increase from the month prior. 2 7 The Spanish influenza resulted in acute illness in 25%–30% of the world population, with over 50 million deaths, whereas COVID-19 has infected nearly 55 million to date, with 1.3 million deaths.

2 6 The mortality rate for pregnant women with the Spanish influenza was 23%–37% and 26% of those who survived but lost their child, whereas the mortality rate of pregnant women with COVID-19 is unknown. 2 5 More countries were spared in the 1918 pandemic, whereas only the smaller Pacific Islands (Soloman Islands and Vanuata) remain COVID-19 free. 2 5 Those aged 25–40 year olds accounted for 40% of deaths from the 1918 influenza, whereas those in the 18–44-year-old range account for only 3.9% of deaths from COVID-19. 2 5 In particular, the mortality rate for the influenza rose to 8%–10% for younger people compared with a 2.5% overall mortality whereas the mortality rate for the 25–40-year-old age range is a mere 0.2% in contrast to the 2.4% overall mortality rate. While the 1918 influenza killed a disproportionate number of 25–40 year olds, COVID-19 mostly affects those over the age of 65, especially those also with comorbidities. 4 As the influenza spread, basic services such as the postal service, telegraph services and some banks were forced to temporarily close operations. 4 A week later on, King Alfonso XIII, the Prime Minister and some cabinet members became ill. 4 However, there is no definite evidence of origination, and most epidemiologists and virologists believe that the virus originated in either the USA or France. 2 The first public news of the epidemic appeared in Madrid on in Madrid’s ABC newspaper hence, it became known as the Spanish influenza. 3 It infected about 500 million people, roughly one-third of the world’s population at that time, and resulted in the deaths of 50 million, including 675 000 Americans. The first wave lasted approximately from 15 February 1918 to 1 June 1918 the second lasted approximately from 1 August 1918 to 2 December 1918 the third lasted approximately from 3 December 1918 to 30 April 1919 and the fourth wave lasted approximately from 1 December 1919 to 30 April 1920. Spanish influenza lasted from 1918 to 1920 and consisted of four waves. The 1918 Spanish influenza is caused by an H1N1 influenza A virus postulated to be of avian origin. Brief historical overview of 1918 Spanish influenza

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