"The King and Queen, who are fully vaccinated with three injections, have mild symptoms and are feeling well, given the circumstances," the palace said in a statement.
The palace said the King, 75, and the Queen, 78, were self-isolating and that work to trace those that they had been in contact with was underway.
The news came as Sweden set a new daily record for COVID-19 cases amid a surge caused by the highly-infectious Omicron variant.
The country registered 11,507 cases on Dec. 30, health agency data showed on Tuesday, as a fourth wave of the virus puts healthcare under renewed pressure.
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