Top US infectious diseases doctor Anthony Fauci has tested positive for coronavirus for the first time in the pandemic.
The National Institutes of Health said Dr Fauci "tested positive for Covid-19 on a rapid antigen test" after avoiding the virus while working to battle the pandemic through the Trump and Biden administrations.
The chief medical adviser to US President Joe Biden has been vaccinated four times and is "currently experiencing mild symptoms". He will be staying home through his infection.
The agency said Dr Fauci had not been in close contact with Mr Biden.
He is the latest senior US official to announce an infection after Secretary of Health and Human Services Xavier Becerra tested positive for Covid-19 for a second time in a month.
Recent research suggests that most of the US population has already had coronavirus, including 75 per cent of children.
Dr Fauci was criticised for claiming the US was "out of the pandemic phase" in an interview this April.
He later said that the country was still fighting a pandemic.
"We certainly cannot say the pandemic is over," Dr Fauci said. "It is not over."
The US Centres for Disease Control and Prevention is reporting more than 100,000 recorded coronavirus cases a day, in a level not seen since February. Hospital admissions are rising nationally.