NECCO Wafers Sweethearts are in short supply on store shelves this year because the company went out of business in July 2018 and closed up their factory.
Spangler Candy Company purchased the brand and plans to relaunch in 2020, which means there are no new packs of Sweethearts for the time being.
So, if you find Sweethearts in stores or online, that candy was manufactured last year.