a shitload, half a million or more worldwide. If it was something new like corona the lockdowns would be far worse than this as there would be 10,000 dying every day rather than 20,000 total in 3 months, a good chunk of which would have probably died anyway given the average age is around 80
This year in the states :
With flu season still winding down, at least 144 children younger than 18 have died, a toll topped only by the 2009 H1N1 pandemic since health authorities began tracking flu data in 2004.
So far this season, the U.S. Centers for Disease Control and Prevention has recorded 36 million flu cases in the U.S., with 370,000 hospitalizations and 22,000 deaths.
https://www.usnews.com/news/health-news/articles/2020-03-20/coronavirus-pandemic-overshadows-a-deadly-flu-season
This is actually down a good chunk on the past couple of years
18/19 in the states 35,000 flu deaths
17/18 in the states 61,000 flu deaths