PHILADELPHIA -- If you're having a hard time finding Grape-Nuts at your local supermarket, you are not alone. The pandemic has come for Grape-Nuts. Supply chain constraints and higher demand for cereal have led to shortages of the product, Kristin DeRock, Grape-Nuts Brand Manager, said in an emailed statement. Grape-Nuts should be "fully back" on shelves in the spring, she said. Though sales of cereal in general were struggling for years, they've grown during the pandemic as customers eat breakfast at home and reach for comfort foods. From 2015 to 2019, the US ready-to-eat cereal market dipped between one and two percent each year, according to data from Euromonitor International. From 2019 to 2020, the market grew by nearly 20% to about $10.6 billion.