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

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.

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.