The top French health authority on Tuesday cleared AstraZeneca's Covid-19 vaccine for use, but advised against giving it to people over 65.
The decision echoes an earlier verdict by Swedish authorities, but is at odds with the European Union which last week approved the vaccine for adults of all ages.
France's HAS health authority also said that pharmacists would be authorised to administer the jabs produced by the Anglo-Swedish firm.
Tuesday's conditional backing for the vaccine comes days after President Emmanuel Macron told reporters that the vaccine was "quasi ineffective for people over 65."
Germany and Italy have also said that other vaccines should be given priority for the elderly.
The age controversy compounds a row over a shortfall in deliveries from AstraZeneca that has forced the EU to recalibrate its vaccination strategy.
The EU Commission said the firm had been able to guarantee just 25 percent of the more than 100 million doses promised, but on Sunday officials said the number would be boosted to 40 million.
Unlike vaccines by Pfizer/BioNTech and Moderna, the one made by AstraZeneca can be stored long-term in ordinary refrigeration units.
However its efficacy is reported at just 60 percent, compared with more than 90 percent for the rival coronavirus vaccines introduced earlier.