A Mississippi man allegedly upset about the COVID-19 vaccination program has been sentenced to two years in prison for threatening federal health officials, federal prosecutors said.

Robert Wiser Bates, 39, of Ridgeland, placed phone calls to the Centers for Disease Control and Prevention in Atlanta in July 2021 and left threatening voicemails for the agency’s director, Rochelle Walensky, according to a news release from U.S. Attorney Darren J. LaMarca.

An investigation found Bates made similar threats towards Dr. Anthony Fauci, who was director of the National Institutes of Allergy and Infectious Disease at the National Institutes of Health, LaMarca’s office said.

Bates pleaded guilty Dec. 19 to charges of making threats in interstate commerce.