Sen. Bernie Sanders (I-Vt.) said Thursday he tested positive for COVID-19, amid a nationwide spike in infections. 

The 82-year-old Sanders, said in a post on X, formerly known as Twitter, he was experiencing “minimal” symptoms and will continue to isolate while working from his home in Vermont.

“I am glad to be fully up to date with the vaccine,” Sanders wrote.

The Senate finished its legislative business for the year last week and won’t be returning for votes until Jan. 8. 

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The U.S. is seeing elevated levels of respiratory illness this winter, and the Northeast is experiencing the highest levels of viral activity, according to the most recent Centers for Disease Control and Prevention wastewater data.  

Nationally, the wastewater viral activity level for COVID-19 is the highest it’s been since the omicron surge in 2022.  

According to data from before Christmas, JN.1 is now the dominant variant. For the two weeks ending Saturday, JN.1 is expected to account for 39 percent to 50 percent of all variants, CDC said. 

“JN.1’s continued growth suggests that the variant is either more transmissible or better at evading our immune systems than other circulating variants. It is too early to know whether or to what extent JN.1 will cause an increase in infections or hospitalizations,” the CDC said, adding that existing vaccines, tests, and treatments still work against JN.1. 

Emergency department visits for all respiratory viruses — COVID-19, flu, RSV — are now showing the biggest acceleration since last year, though the most COVID-related visits are among people 65 and older.