Originally Published: 16 AUG 22 09:37 ET

Updated: 16 AUG 22 10:05 ET

By Betsy Klein and Kate Bennett, CNN

(CNN) -- First lady Dr. Jill Biden has tested positive for Covid-19 and is experiencing mild symptoms, her spokesperson said Tuesday.

"After testing negative for Covid-19 on Monday during her regular testing cadence, the First Lady began to develop cold-like symptoms late in the evening. She tested negative again on a rapid antigen test, but a PCR test came back positive," said Elizabeth Alexander, her communications director.

The first lady, who is double vaccinated and twice boosted, is taking Paxlovid, Pfizer's antiviral drug, according to Alexander, who told CNN that Biden received her second booster shot in April.

A person close to the first lady told CNN Tuesday morning that Jill Biden is "feeling good" and has "common cold"-like symptoms. The first lady is 71 years old, making her the oldest sitting first lady in modern American history. She exercises several times a week, taking classes at local barre gyms.

This is the first time she has had Covid-19, according to Alexander.

The first lady is currently in Kiawah Island, South Carolina, with President Joe Biden, who is due to return to Washington for a bill signing later Tuesday.

"She is currently staying at a private residence in South Carolina and will return home after she receives two consecutive negative Covid tests," Alexander added.

The President, who recently recovered from his own case of Covid-19, continues to test negative, press secretary Karine Jean-Pierre said on Twitter. She added added that President Biden will follow US Centers for Disease Control and Prevention guidance on close contacts and wear a mask for 10 days "when indoors and in close proximity to others."

"We will also increase the President's testing cadence and report those results," Jean-Pierre added.

President Biden initially tested positive for Covid-19 on July 21. He isolated while taking a course of Paxlovid, eventually testing negative on July 27. However, on July 30 he tested positive for the virus again as he experienced a rebound case, which happens to some people who take Paxlovid. He against entered isolation and eventually emerged from the White House on August 7 after testing negative for two days in a row.

This is a breaking story and will be updated.