There are instances of similar pandemics in the past. But they occurred long time back. The last one of such a scale occurred in 1918-20 (Spanish flu pandemic). And that was more than a hundred years ago. Back then, around 500 million people got infected and 4% to 10% of them died. This time, the number of infected has already crossed the 100 million mark, and the fatality rate is 1% to 2%. However, we can't directly compare these two. Back then, the world population was much lower. And the medical science was not that advanced. So a lot of people died due to lack of quality medical care.
Spanish flu is not the deadliest pandemic ever reported in human history. That distinction goes to the Black Death (1346–1353). Up to 200 million people died in this pandemic. This pandemic reduced the world population by anywhere from 10% to 40%.