French flu is another type of the influenza virus – mainly H1N1 and some H3N3 cases, according to Now Healthcare Group’s Medical Director, Dr Ben Coyle.
The flu virus will have similar symptoms to the deadly Aussie flu, he said.
Signs of the condition to watch out for include a fever, headaches and aching muscles.
The warning came after the French Ministry of Health warned that the flu epidemic would continue to grow in France.
“The French flu is another variation of flu [mainly H1N1 and a few H3N3 cases], so basically another subtype of influenza A or B usually,” Dr Coyle told Express.co.uk.
“It will have similar symptoms, so aching, high temperature, sore throat, runny nose, congestion, headaches, weakness/exhaustion and lethargy.
“Those most likely to get it, and to suffer a more severe illness, are the elderly or immunocompromised [long-term steroids, those on immune-modifying drugs or chemotherapy for instance], those with long-term health conditions, children and pregnant ladies.”
The flu vaccine is the best way to lower your risk of becoming infected with the virus, he added.
Washing your hands regularly, and avoiding crowded spaces could also help to stop the virus from spreading.
If you become infected with French flu, always cover your mouth and nose when coughing or sneezing, said Dr Coyle.
The flu vaccine could help to lower your risk of infection, too, he said.
On Friday, the French Ministry of Health said all regions of the country – beside Corsica – were affected by the flu epidemic.
During the week immediately after Christmas Day, almost 12,000 people visited a doctor due to flu, or flu-like illness, it said.
Almost half of the cases were in children under-15. One in five of these cases led to hospitalisation.
But, the epidemic is yet to peak, it warned.
“This year, the epidemic of influenza is of an exceptional magnitude, by the number of cases, and risks exceeding those of the last two years,” the Ministry said.
“To limit the epidemic of seasonal flu, it is essential that everyone adopts simple preventive actions to limit the circulation of the flu virus, especially in communities and on public transport where it is easily transmitted.”