The COVID-19 mortality rate made it the third leading cause of death in the United States in 2020 after heart disease and cancer, according to a government report released on Wednesday. COVID-19 was the primary or contributing cause of 377,883 deaths in the United States last year, with a particularly high toll among the elderly, the U.S. Centers for Disease Control and Prevention (CDC) analysis found.. The CDC said that the overall U.S. mortality rate increased for the first time since 2017, by nearly 16 percent, to 3,358,814 deaths. The jump was driven by COVID-19, which accounted for an increase of 11.3 percent. The overall death rate was lowest among children aged 5 to 14 years, and highest among people over age 85, the report found. A total of 134 children aged 14 and under died from COVID-19 in 2020, while 120,648 people aged 85 and older died from the disease. …