Seven residents of a nursing home in Belgium have died after being infected with the Colombian variant of the coronavirus, despite being fully vaccinated, the virology team that conducted tests said on Friday.

The variant of Covid-19 that originated in Colombia, or B.1.621, has been detected in recent weeks in the United States but cases in Europe have been rare.

The seven people who died at the nursing home in the Belgian town of Zaventem, near Brussels, were all in their 80s or 90s, and some of them were already in a poor physical condition, said Marc Van Ranst, a virologist at the University of Leuven which conducted tests on the strain found at the nursing home.

“It is worrisome,” Van Ranst said, commenting on the fact that the residents died despite being fully vaccinated against Covid-19.

So far, scientists do not know if the Colombian variant is more transmissible than other variants, he said.

In Belgium, the variant currently accounts for less than 1 per cent of known cases of Covid-19, he said, compared to 2pc of cases in the United States and more than that in Florida.

At the nursing home in Zaventem, 21 residents were infected with the variant along with several members of staff, Van Ranst told Reuters. The infected staff experienced only mild symptoms.

Van Ranst said the dominant coronavirus variant in Belgium with around 95pc of infections is the Delta, first discovered in India, followed by the Alpha that was previously dominant in Britain.

Additional tests will be run on Friday to rule out any possibility that the nursing home residents died from a different variant of the virus or a different respiratory disease, Van Ranst said.

“It is unlikely but not impossible,” he said.