The head of state of Monaco announced he had tested positive for the illness on March 19 after being anonymously tested three days earlier, according to People.
The Prince's Palace has since released a thank-you message from the 62-year-old.
"His Serene Highness Prince Albert has been moved by all the good wishes He has received from all around the world," the statement reads. "HSH wants to thank all the people that have sent Him their support.
"This Sovereign Prince remains confined in His apartments inside the Palace. His is still working with His close collaborators in accordance with the health measures. His health, controlled several times during the day by doctors, doesn't inspire any concern."
Albert told People he's "feeling okay" and has "flu-like symptoms" but seems to thankfully be a mild case.
"I have to be careful because of my recent medical history fighting off pneumonia a couple of years ago," he told the publication.
He also said he has no idea how he got it and had been "using hand sanitizers and all that" for weeks in an attempt to avoid infection.
"It can hit anybody of any age," he stressed.Thankfully, his wife Princess Charlene and their twins Prince Jacques and Princess Gabriella are symptom-free at the moment. They're not at the Palace, though, and he told People they'd been sent to Roc Agel, the family's country house. He said he will join them when he is recovered.
"Look, we're going to get through this," he told People. "But everyone has to follow the recommendations. Yes, it's a nuisance and yes, being confined is very limiting – but it's the only way to stop the spread of this virus."
Albert was the second royal to be diagnosed with COVID-19. Before he revealed his health issue, the prince placed Monaco on lockdown earlier this week.
Karl von Habsburg, the ancestral Archduke of Austria, announced he'd tested positive for the illness on March 17. He described it as "annoying" and said he was "fine" and thought his symptoms had been the flu, but said he's following doctors' orders with regard to recovering.
As of this writing, the World Health Organization says nearly 210,000 cases of COVID-19 have been reported in 168 countries. Monaco has had nine of those cases. The illness has caused more than 8,700 deaths worldwide.