The UK has been hit by a handful of major virus outbreaks over the past 100 years.
By far the most severe was the so-called ‘Spanish flu’ pandemic of 1918-19, which overlapped with the end of the First World War.
Globally the outbreak is estimated to have killed between 20 and 50 million people. In the UK, the number of fatalities was around 200,000 – equivalent to roughly 0.5% of the pre-war population.
Spanish flu was a particularly severe strain of the H1N1 influenza virus. Almost a century later, another strain caused the ‘swine flu’ outbreak of 2009-10.
This was a very mild pandemic compared with its forerunner, but is still estimated to have caused around 18,000 deaths worldwide including 457 in the UK, according to government figures.
Swine flu is believed to have emerged in Mexico. The precise origin of Spanish flu remains unclear.
There have been two moderate pandemics in recent history: so-called ‘Asian flu’ and ‘Hong Kong flu’.
Asian flu began in southern China and spread around the world in 1957-58.
Up to four million deaths have been attributed to this outbreak, including around 33,000 in the UK.
The Hong Kong flu pandemic of 1968-69 also began in southern China and led to a similar number of deaths worldwide – though in the UK the number was higher than for Asian flu, totalling around 80,000.
In recent years there have been two threatened pandemics that did not materialise, both from strains of coronavirus: Serious Acute Respiratory Syndrome (SARS) in 2002-03, and Middle East Respiratory Syndrome (MERS) in 2012.
Neither of these outbreaks have been linked to any deaths in the UK.
(All figures have been taken from the UK government’s coronavirus action plan.)