Duchess Kate was to attend special events marking the National Health Service's 73rd anniversary on July 5, but won't be able to because she's self-isolating after coming into contact with someone with COVID-19.
The Duchess of Cambridge had contact with the individual last week, Buckingham Palace said in a statement.
"Her Royal Highness is not experiencing any symptoms, but is following all relevant government guidelines and is self-isolating at home," the statement said.
Kate has had both of her vaccine doses, according to HELLO! UK, and was told the afternoon of July 2 about the individual testing positive. As a result, she started isolating that day.
The duchess was out several times last week, including attending matches at Wimbledon on July 2 and helping out in the All England Lawn Tennis and Croquet Club's kitchen. She also stepped out with Prince William and Prince George to watch England's Round of 16 Euro 2020 game against Germany at Wembley Stadium on June 29.
Before both engagements, she took lateral flow tests and was found to be negative for COVID-19 and wore a mask when required at both events.
The Royal Household has its own coronavirus testing regime, which sees Kate tested twice a week for the illness.
Last year, William and Prince Charles both contracted the coronavirus, as did Princess Michael of Kent. The Duke of Cambridge's case was reportedly a bit more rough than the Prince of Wales's. Charles isolated at his and Duchess Camilla's Birkhall home on the Royal Family's Balmoral estate while he recovered from the virus in late March 2020. William reportedly came down with it the following month.