PARIS - The fifth wave of COVID-19 hitting France has not yet reached its peak, government spokesman Gabriel Attal said on Wednesday, and the cabinet's top adviser on the coronavirus indicated a fourth vaccine shot to fight the disease was possible.

"The peak is clearly not behind us, the pandemic continues to gain ground," Attal said during a press briefing following the weekly cabinet meeting, though adding the pace of increase in daily new cases seemed to be slowing somewhat.

"But it's still spreading quickly and will continue to do so in the coming weeks," he said, days after France announced new restrictions to contain the Delta variant-fuelled spread of the virus, including the closure of nightclubs ahead of Christmas and a tightening of social distancing measures. 

The seven-day moving average of new confirmed new infections set a new 2021 high of more than 44,500 on Tuesday.

Earlier the government's top COVID-19 adviser Jean-Francois Delfraissy said France will "suffer again" as this new wave was bound to take a toll on an "already tired hospital system".

France, whose adult population is more than 90% fully vaccinated, is hoping a national campaign inviting everyone over age 18 to get a third vaccine - or booster shot - as fast as possible will avoid the need for tougher curbs on daily life.

"For now, there's a call for one booster shot. Will that be enough I don't know. Maybe we'll need a fourth shot," Delfraissy said, adding that vaccines were mainly effective against severe forms of COVID-19 and less so against transmission of the virus.

(Reporting by Benoit Van Overstraeten Editing by GV De Clercq and Mark Heinrich) ((; +33149495339;))