Prince William was just forced to host a palace tea party alone after his wife Kate Middleton went into self-isolation due to exposure to COVID-19.

“Last week, The Duchess of Cambridge came into contact with someone who has subsequently tested posted for COVID-19,” a palace spokesperson told Fox News. “Her Royal Highness is not experiencing any symptoms, but is following all relevant government guidelines and is self-isolating at home.”

This came as William and Kate were set to attend a service at St. Paul’s Cathedral on Monday morning to mark the birthday of the National Health Service (NHS), which was established 73 years ago. William went solo and hosted a tea party at Buckingham Palace in which he paid tribute to healthcare workers.

At this event, William met with respiratory ward nurses, counselors, care workers, as well as staff members in non-clinical roles, such as catering managers and housekeeping coordinators.

Guidelines issued by the British government state that Kate has to isolate at home for ten days following exposure. She is vaccinated for COVID-19, getting her first shot back in May.

This comes after Kate sat out the unveiling of a statue of Princess Diana at Kensington Palace last week. A source previously revealed that Kate “desperately wanted” to attend the ceremony.

“Out of respect for [Prince] Harry and William, [the royal family] wanted it to be just about Diana’s sons and not a huge public affair,” a source told US Weekly. “Kate was definitely supporting William while physically not being there and really wanted to attend, but the family as a whole decided it was best for the kids and her to stay home.”

The source went on to say that the royal family decided “a few weeks ago” who would be at the ceremony. “Kate watched from afar with” her and Prince William’s three young children as the statue was unveiled.

While speaking to the attendees at the small event last Thursday, the brothers said, “Today, on what would have been our mother’s 60th birthday, we remember her love, strength and character — qualities that made her a force for good around the world, changing countless lives for the better.”

“Every day we wish she were still with us, and our hope is that this statue will be seen forever as a symbol of her life and her legacy,” William and Harry added.