Many mutations of standard influenza. Flu vaccine doesnt cover all of them. How many of those 80,000 deaths were vaccinated?
https://www.cdc.gov/flu/about/season/flu-season-2017-2018.htm
This site says the vaccines were about 40% effective, and that was a very good year. Some years they are only 15% effective.
Note that the deaths from the standard flu are estimates.