France's top health official has highlighted a "worrying trend" in Covid-19 infection and hospitalisation numbers across the country even before the effects of gatherings over the Christmas period begin to manifest.
Salomon highlighted four key areas of concern: coronavirus transmissions during family gatherings, the resumption of school, two new variants of the virus from the UK and South Africa, and the weather. These were the main factors behind France's tightened curfew in 15 departments, which came into effect at 6pm on Saturday.
"The earlier the curfew starts, the more effective it is," Salomon said, adding that the tougher curfew, two hours earlier than the rest of the country, was imposed in regions where colder winter temperatures have set in, allowing the coronavirus to circulate more freely.
The departments targeted are also border areas with more movement of people, or rural parts with a more vulnerable populations, he explained.
Paris has so far been spared the 6pm curfew, but it and the rest of France could also be hit if positivity and reproduction rates rise significantly.
The situation in overseas departments in the Caribbean, where many French travelled for the end of year festivities, is being closely monitored. Other mainland areas under watch are Bourgogne-Franche-Comté, the south-eastern PACA and Auvergne-Rhône-Alpes regions.
The government is to make a new assessment of the Covid situation on 7 January. It has already announced that theatres, cinemas and museums will not be allowed to reopen, as had been hoped by France's desperate culture sector.
Ski resorts also face a continued slump, with ski lifts to remain closed. "We are also preparing sports centres and restaurant and café owners for the very likely decision that they will not be able to reopen on 20 January," sources from the office of Prime Minister Jean Castex said.
Ahead of the "Christmas effect", France's rate of infection has already sharply increased from average figures of around 10,000 new cases per day before the holiday season.
"On Monday 28 December, there were 22,480 new cases recorded, more than the two previous Mondays. The 19,775 cases on 29 December is higher than the two previous Tuesdays," said Salomon.
"Hospital admissions remain persistently high, with between 1,000 and 1,200 per day. Some 25,000 people are hospitalised, including 2,600 in intensive care."
Salomon urged citizens to continue to respect barrier gestures, to download the TousAntiCovid tracking app and to self-isolate yourself in the event of the slightest doubt.
France began its vaccination campaign in elderly healthcare centres on 27 December, but the government has come under fire for making slow progress.
An impatient President Emmanuel Macron has slammed the pace of the vaccine rollout, saying it was as slow as a "family stroll", and that it "does not meet the needs of the moment, nor the needs French".
In a recent survey, already strong French resistance to the vaccine rose further still, with only 40 percent of French said they intend to get the jab.