Argentina on Saturday confirmed that President Alberto Fernandez has tested positive for the new coronavirus, saying the first-term Peronist leader was in generally good health despite having suffered a headache and light fever.

Fernandez, who turned 62 on Friday, had previously said on Twitter that he was in isolation under standard COVID-19 protocols after an initial test showed he had the virus. He had received Russia's Sputnik V vaccine early this year.

"The diagnosis of COVID-19 infection is confirmed. The clinical picture is mild due in large part to the protective effect of the vaccine received," said a statement issued by the president's doctor, Federico Saavedra.

Fernandez has remained on the job since the diagnosis.

"I would have liked to end my birthday without this news, but I am in good spirits," Fernandez added.

Argentina's vice president is the country's former leader, Cristina Fernandez, who is no relation to the president.

Russia's Gamaleya Institute, which developed the Sputnik V vaccine, issued an open statement to Alberto Fernandez, saying that Sputnik V is 91.6% effective against infection and 100% effective against severe coronavirus cases.

"The vaccination ensures quick recovery without severe symptoms," it said.

Argentina has been on a lockdown of varying degrees for more than a year against the pandemic. COVID-19 has killed more than 56,000 people in the country to date. Some 682,868 Argentines have been fully vaccinated so far, with older people and healthcare workers getting priority, the government says.