U.S. Sen. Lindsey Graham announced Monday that he has tested positive for COVID-19 after being vaccinated for the virus. In a statement issued by his office, Graham said he began experiencing flu-like symptoms on Saturday night. He said he went to the doctor Monday morning and "was just informed" of his positive test result. "I feel like I have a sinus infection and at present time I have mild symptoms," Graham said. "I will be quarantining for ten days. “I am very glad I was vaccinated because without vaccination I am certain I would not feel as well as I do now," Graham said. "My symptoms would be far worse.” Graham, 66, is a Republican from Seneca who is serving his fourth term in the Senate. He's the ranking member on the Senate Budget Committee. His diagnosis came a day after Dr. Anthony Fauci, the chief medical adviser to President Joe Biden, acknowledged some breakthrough infections are occurring among the vaccinated.