(CNN) Second gentleman Doug Emhoff tested positive for Covid-19 on Tuesday, according to a statement from the vice president's office.
"Earlier today, the Second Gentleman tested positive for Covid-19," said Sabrina Singh, deputy press secretary for Vice President Kamala Harris. "Out of an abundance of caution, the Vice President will not participate in tonight's event. The Vice President tested negative for Covid-19 today and will continue to test."
Emhoff's positive test is the first known case of Covid-19 among the first or second families since President Joe Biden and Harris took office in January 2021.
"I tested positive for COVID. My symptoms are mild and I'm grateful to be both vaccinated and boosted," Emhoff said on Twitter Tuesday night. "If you have yet to get vaccinated and boosted, please don't wait."
A White House official told CNN that Emhoff was "not experiencing symptoms ahead of his morning events," but having "mild symptoms this afternoon."
"He took an antigen test and tested negative. Out of an abundance of caution he then took a PCR test, and tested positive," the official told CNN.
Harris was set to participate in an Equal Pay Day event at the White House Tuesday evening that began just as Emhoff's test results were released. In a potential sign of how last minute the vice president was pulled out of the event, there was an empty chair for her on stage for the Equal Pay Day event. The White House Twitter account had also advertised upcoming remarks from Harris in a message posted at 6 p.m. ET, just before the event was to begin.
Biden addressed Harris' absence at the event, saying, "Kamala chose not to take a chance since he tested positive -- by the way, he's fine, but out of an abundance of caution, she decided not to join."
White House press secretary Jen Psaki said earlier this week that the President was last tested on Sunday and tested negative. CNN has asked the White House for more information on when the President will be tested next.
The vice president attended an event with Biden at the White House earlier Tuesday as he signed a $1.5 trillion government funding bill into law. Harris stood by Biden's side as the President gave remarks, and later stood in the crowd of lawmakers who attended the signing ceremony.
Neither Harris nor Biden wore a mask at the event. Inside the White House, in accordance with federal public health guideline changes in recent weeks, officials and visitors have not been required to wear masks or socially distance. Covid-19 cases in Washington have precipitously declined since their peak in early January, when the country was facing a wave of Omicron variant cases.
Earlier Tuesday, Emhoff visited a communal garden in the nation's capital for an event. The second gentleman gardened outside during the event.
CNN has asked the White House for comment on when the last time Emhoff was in contact with Biden and for more information on his test. A White House official said Biden is not considered a close contact to the second gentleman.
Harris has previously had a close brush with Covid-19. The vice president tested negative last summer after a meeting with Texas House Democrats, several of whom later tested positive for the coronavirus.
According to US Centers for Disease Control and Prevention guidelines, fully vaccinated people can "refrain from quarantine following a known exposure if asymptomatic." Harris is fully vaccinated and boosted, as is her husband.
This story has been updated with additional reporting.