Ministers are urging the most vulnerable and those who were first-vaccinated at the start of the year to get the third jab.
The health minister advised that six months must have passed between the dates of the first injection and someone's planned third jab.
Vaccination slots are being made available for those aged 65 and above.
At a national level, 49.6 million people in France have had at least one vaccination, with a total of 46.7 million French citizens fully vaccinated.
Disparity between regions
Residents of nursing homes already have a high rate of full-vaccination.
Just over 90 percent have completed their vaccination cycle, according to data from Public Health France as of September 9.
However, strong disparities still exist between nursing homes in mainland France and in its overseas regions.
Some 95 percent of care home residents in the region of Haute-Marne are fully vaccinated.
By comparison, the French Caribbean islands of Guadeloupe and Martinique have only fully jabbed 52 percent and 53 percent of elderly residents.
The two islands have been hard hit by the fourth wave of cases, with France sending healthcare workers from the mainland and evacuating some patients to hospitals back in France as local medical facilities were overburdened.
For the islands, they are still focusing on rolling out first COVID-19 jabs to as many people as possible, with the third-shot booster campaign not a priority in those regions for now.
Cover picture: A woman gets her COVID-19 booster jab in Paris. Credit: Thomas Coex/AFP