Dot is referring to Spanish Flu of 1918=1919. Up to 100 milion people died worldwide. One of my relatives had it and survived but was severely impaired for the rest of her life.
Are you thinking of Asian Flu in 1957? Up to 4 million people died. I caught it whilst on an assignment to the UK (London). I was billeted in a bachelor flat in North Kensington, went back there from work this Monday feeling rough, consequently lay down for an hour before going out to find a cafe for dinner. Woke up feeling diabolical, must have fallen asleep as it is now morning, showered and shaved, nothing else to do so I'll go to work. Purchased a newspaper at Ladbroke Grove Station. Reading it on the train I realised the date was wrong. I asked the person sitting next to me how a newspaper could be 5 days in advance with the date, only to find that this was the correct date. I had been unconscious with Asian Flu for 5 days!! Talk about a mini Rip van Winkle!! Got off train, collapsed in Lombard Street and finished up in Hospital for 3 weeks!!