STOCKHOLM, June 23 (AFP) - The highly contagious Delta variant could soon account for 90 per cent of new coronavirus cases in the EU, the bloc's disease control agency said Wednesday, urging members to spur vaccination drives.

While the Alpha variant first discovered in the UK is the predominant strain now circulating in the European Union, that is expected to change quickly, the European Centre for Disease Prevention and Control said.

"It is very likely that the Delta variant will circulate extensively during the summer, particularly among younger individuals that are not targeted for vaccination," Andrea Ammon, the centre's director, said in a statement.

The Delta variant, first identified in India, is more infectious than other strains, she said, adding "that by the end of August it will represent 90 per cent" of new cases in the EU.

The centre's warning comes as Russia warned of an "explosive" surge in infections that has been made worse by low rates of vaccine uptake.

The UK has also seen the Delta variant become dominant, but has been shielded by a successful vaccination campaign, with 82.5 per cent of adults having had at least one jab and 60 percent fully protected.

"It is very important to progress with the vaccine rollout at a very high pace" in order to stop the spread of the variant and mitigate its health impact, the centre said.

To date, about 30 per cent of the over-80s and 40 per cent of the over-60s in the EU are still not fully vaccinated, the centre's data show.