The Delta variant, identified for the first time in India, could account for 90 percent of new Covid cases in the European Union in the coming months, the bloc's disease control agency said Wednesday.

"Based on the estimated transmission advantage of the Delta variant and using modelling forecasts, 70% of new SARS-CoV-2 infections are projected to be due to this variant in the EU/EEA by early August and 90% of infections by the end of August," the European Centre for Disease Prevention and Control (ECDC) said in its regular threat assessment brief.

The ECDC warned that because primo-vaccinated people are less protected against it, "it is likely that the Delta variant will circulate extensively during the summer, particularly among younger individuals that are not targeted for vaccination."

"This could cause a risk for the more vulnerable individuals to be infected and experience severe illness and death if they are not vaccinated," it added.

The ECDC's modelling scenarios indicate that any relaxation over the summer months of the stringency of non-pharmaceutical measures that were in place in the EU/EEA in early June could lead to a fast and significant increase in daily cases in all age groups.

Those over the age of 50 would be most impacted, "with an associated increase in hospitalisations, and deaths, potentially reaching the same levels of the autumn of 2020 if no additional measures are taken," the ECDC said.

ECDC Director, Dr Andrea Ammon, also stressed that "it is very important to progress with the vaccine roll-out at a very high pace."

"At this stage it becomes crucial that the second vaccination dose is administered within the minimum authorised interval from the first dose, to speed up the rate at which vulnerable individuals become protected," she went on.

"The Delta variant is more transmissible than other circulating variants and we estimate that by the end of August it will represent 90 percent" of new cases in the EU, she added.

According to the ECDC, more than 57% of adults in the EU/EEA have so far received at least one dose of the different vaccines. More than a third have received a full vaccination course.