In a tweet, Mr Graham, said he was experiencing “flu-like symptoms” but felt they would’ve been worse had he contracted Covid-19 prior to getting vaccinated.
“I am very glad I was vaccinated because without vaccination I am certain I would not feel as well as I do now. My symptoms would be far worse,” Mr Graham, 66, wrote on Monday.
His symptoms first started on Saturday, the South Carolina senator said, which encouraged him to visit a doctor on Monday morning.
“I feel like I have a sinus infection and at present time I have mild symptoms,” the Republican added. “I will be quarantining for ten days.”
Covid-19 vaccines are highly effective against preventing severe disease, hospitalisations, and deaths from the novel virus, but a small share of vaccinated individuals have become infected.
These “breakthrough cases”, as they are called, have occurred in an estimated 0.08 per cent of the more than 164.2 million people who have received the Covid-19 vaccine, according to an analysis by NBC News.
Mr Graham, like other senators, has not been wearing a mask around the US Capitol for some time, according to congressional pool reporters.
CNN’s Manu Raju reports that Democratic Senator Joe Manchin had a small group of lawmakers on his houseboat this weekend and Mr Graham was among them. The Independent has not independently confirmed this detail.
Mr Manchin’s office declined to comment on the report.
“Senator Manchin is fully vaccinated and following the CDC guidelines for those exposed to a Covid-positive individual,” said his spokeswoman Sam Runyon when speaking to CNN.
The Untied States is currently battling a surge in Covid-19 infections due to the highly contagious Delta variant, with the country recording close to 80,000 new daily cases per day.
Health officials have said that while vaccines might be less effective at preventing infection, they were still about 90 per cent effective in preventing severe disease. About 99.9 per cent of vaccinated individuals who contracted Covid-19 survived.
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