The 1918-1920 flu pandemic, often called ‘Spanish flu’, infected around 500 million people worldwide, killing as many as 50 million. In comparison, the coronavirus SARS-CoV-2 has, at the time of writing, killed over 900,000 from almost 30 million confirmed cases.
The influenza virus that caused Spanish flu eventually mutated into a less dangerous strain, but if an outbreak of the original Spanish flu strain happened today, it’d likely be far less deadly than a century ago.
When Spanish flu struck in 1918, scientists thought it was transmitted by bacteria, and it wasn’t until 1931 that the influenza virus was discovered. Today, we have a good understanding of flu viruses and how they spread, and we can develop and make vaccines for new flu strains in a matter of months.
Also, in the 1918-1920 pandemic, an estimated 95 per cent of fatalities were caused by bacterial pneumonia (flu infections make it easier for certain bacteria to grow in the lungs). Today, most of these cases could be treated with antibiotics, and we also have the added resource of mechanical ventilators, for the more severe cases.
Jeremy Rossman is a Senior Lecturer in Virology and President of Research-Aid Networks, University of Kent. His research focuses on the process of infectious disease outbreaks, and he has contributed to studies published in journals including PLoS Pathogens, Bioinformatics and Cell.