SALISBURY, (United Kingdom): Queen Elizabeth II on Thursday made her first public visit outside a royal residence since the start of the coronavirus outbreak, visiting a top secret research lab but appearing without a face mask.

The 94-year-old monarch and her grandson Prince William visited the Defence Science and Technology Laboratory (Dstl) at Porton Down in southwest England, which has been helping to study Covid-19.

"It's doubling itself again," the queen remarked when discussing the current second wave. Being told it was on the rise, she said: "Well, I suppose it was expected?"

"Predicted ma'am, yes," replied Professor Tim Atkins, who coordinated Dstl's response, to which the monarch responded: "With all these horrible new things..."

The queen and William did not wear face masks but arrived separately and stayed two metres apart, while aides said all 48 people due to come into close contact with the royals had been tested for coronavirus.

It was the monarch's first public engagement outside one of her homes - where she has had a reduced household staff known as "HMS Bubble" - since she attended a Commonwealth Day service at Westminster Abbey on March 9.

As coronavirus swept across the UK, she and her husband Prince Philip, 99, retired first to Windsor Castle west of London, as a precaution because of their age.