More than 670 professional and volunteer firefighters in France had complained that compulsory vaccines violated their rights.
A European Court has dismissed a complaint by French fighters against COVID-19 vaccinations being mandatory.
More than 670 professional and volunteer firefighters had complained about compulsory vaccines and said the measures violated their privacy rights.
But the European Court of Human Rights has rejected their application and said that the complaint fell outside their scope.
But the ruling did not rule out future cases on the matter if mandatory vaccinations cause "a real risk of irreparable damage" to the firefighters.
The SUD SDIS union which brought the case has described the verdict as an "extreme disappointment".
Rémy Chabbouh, national secretary of the union, told AFP that they would continue fighting.
Chabbouh also expressed fear that "a large proportion" of his colleagues will be radicalised because of the mandatory vaccination requirements.
Earlier this month, France made COVID-19 vaccines mandatory for healthcare workers, who could will from November face a suspension of their contract without pay if they refuse vaccination.
On Monday, SUD SDIS filed an unlimited national strike notice to demand "the withdrawal" of the vaccination obligation.
"The aim is not at all to increase the number of strikers or protesters, but to protect staff who do not wish to be vaccinated and who are waiting for a solution", said Chabbouh.