PARIS, Dec 6 (Reuters) - France will close nightclubs ahead of Christmas and tighten social distancing measures in response to the emergent Omicron variant of the coronavirus but there is no need for new lockdowns or curfews, Prime Minister Jean Castex said on Monday. Castex said a fifth wave of the pandemic was now surging through the country. But he said that with 52 million people now vaccinated - nearly 90% of those eligible - the situation is better than in previous outbreaks and there is no need for drastic measures to save Christmas. Health Minister Olivier Veran said the combination of vaccination booster shots and more rigorous social distancing would allow France to avoid renewed lockdowns currently being imposed in several European countries. "We want to get through this wave of the pandemic without new constraints on the whole of the French population, whether they are vaccinated or not," he said. From Friday, nightclubs will be shut for four weeks and the government also called on citizens to voluntarily limit private and professional gatherings, while tightening requirements for mask-wearing in schools. From Dec. 15 children aged five to 11 who are overweight or who have a serious health condition will be offered access to vaccination. Children over the age of 12 can already be inoculated. Veran said France would get its first deliveries of Pfizer COVID vaccines for children from Dec. 13 and that he hoped vaccinations would be available to all children from Dec. 20. There are about six million children aged five to 11 in France, and 350,000 in that age bracket who are overweight or who have serious health conditions. Veran also said France had identified 25 positive cases of the Omicron variant - 21 imported by people returning from southern Africa and the rest the result of local infection. He said the infection rate had started to slow down, while remaining high. On Monday, the seven-day moving average of new cases was up by 44% compared to a week earlier, down from week-on-week increases over 80% seen two weeks ago.