Paris, Jun 23 (IANS): The Delta variant of the novel coronavirus "must be of concern to us," French government spokesperson Gabriel Attal warned on Wednesday, urging individual and collective vigilance to prevent a spiral of infections due to the more contagious variant.

"There is a threat (of epidemic resurgence) linked to the Delta variant," Attal told RMC radio. "We can see that things can go very quickly ... and that requires individual and collective vigilance."

First identified in India, the Delta variant is the fastest and fittest coronavirus strain that will "pick off" the most vulnerable people, the World Health Organisation said on Monday.

In France, the variant is now responsible for 9 to 10 per cent of the around 2,000 new Covid-19 cases per day. It may prompt an epidemic resurgence in September or October, predicted Jean-Francois Delfraissy, head of the scientific council that advises the government on Covid, Xinhua reported.

The government spokesperson reiterated that vaccine is a weapon against the epidemic.

"The more we continue to be vaccinated, the more we will be able to protect ourselves against variants," he said.

As of Tuesday, over 32.4 million people in France, or 61.8 percent of the adult population, have received at least one vaccine jab. Some 17.1 million people have completed their vaccination, representing nearly one-third of the adult population, data from the Health Ministry showed.

The French government targets 40 million first shots and 35 million fully vaccinated people by the end of August.