For the first time since the start of the pandemic, the coronavirus has reached an Argentine research base in Antarctica, causing the evacuation of nine unvaccinated staff who tested positive for COVID-19, an official said Thursday.

Twenty-four of the 43 scientists and military personnel resident at Argentina's La Esperanza base have been infected, Patricia Ortuzar of the government's National Directorate of the Antarctic told AFP.

Nine of the 24, who have no symptoms, were evacuated to Buenos Aires by helicopter as a precaution.

They had been in Antarctica since before the start of Argentina's vaccination campaign in 2021, and were due to travel to the capital to be jabbed.

The situation at La Esperanza base was "under control," said Ortuzar.

The other 15 coronavirus-positive staff, also asymptomatic, remained at the base with the rest of the team.