Royal officials said they took the rare step of commenting on the monarch's health in order to prevent inaccuracies and further speculation. The queen "decided that she would let it be known she has had the vaccination," the palace statement said.

On Dec. 8, Britain became the world's first country to begin a mass vaccination drive against the coronavirus. The government says it is aiming to deliver the first vaccine doses to some 15 million people in the top priority groups by the middle of February.

That includes everyone over age 70, as well as frontline health care workers, care home residents and anyone whose health makes them especially vulnerable to the virus.