PARIS -- France's top health advisory body is recommending that the AstraZeneca coronavirus vaccine only be used on people under 65, citing lack of sufficient data about its effectiveness in older people.

The decision could shake up the French vaccination strategy, because the country has prioritized nursing home residents and people over 75. France had counted on the AstraZeneca vaccine for a large part of its upcoming inoculations, until the company announced delays affecting countries around Europe and the world.

The French guidance differs from that given by the European Medicines Agency, which authorized AstraZeneca's vaccine for use in all adults throughout the European Union on Friday, amid criticism the bloc is not moving fast enough to vaccinate its population.

Health authorities in Germany and other countries have raised concerns that the Anglo-Swedish company didn't test the vaccine in enough older people to prove it works for them, and indicated they would not recommend it for people over 65.

In guidance issued Tuesday, France's High Authority for Health said it “recommends that the vaccine ... be given preferentially to people under 65.” It says it will review this guidance when AstraZeneca has more data on the vaccine's effectiveness in older people.

The French government depends on the High Authority's guidance, and will announce Wednesday how this affects its plans. Health officials have said they constantly adapt vaccine strategy based on availability of doses, demand and regulatory guidance.

President Emmanuel Macron met Tuesday night with international vaccine producers and major pharmaceutical companies that have an industrial site in France to discuss ways to “quickly” and “significantly” boost short-term production capabilities in France and in Europe.

The meeting comes amid criticism of the EU's handling of its collective vaccine strategy across the 27 member states.

France has seen among the world's highest numbers of virus infections and deaths, which have been steadily rising in recent weeks.