Macron announces a new vaccine rule for people 65 or older in France.

President Emmanuel Macron of France announced the tightening of a key anti-coronavirus measure on Tuesday, as virus cases kept rising across France and the rest of Europe.

In a televised speech, Mr. Macron called the trends worrying and urged people to get vaccinated as soon as possible.

People over 65 years old, he said, will now have to get a booster shot to remain eligible for a vaccine “passport” that is required to gain access to restaurants, museums, long-distance trains and other public places. The new rule takes effect Dec. 15.

France already has a fairly high vaccination rate, with 69 percent of its population fully vaccinated. Even so, reports of new Covid-19 cases have been increasing in recent weeks, as have hospital admissions, which Mr. Macron called an alarm signal.

An average of 40 Covid-related deaths a day are being reported by hospitals. The figure has risen by 60 percent in a week, though it remains only one-tenth of the figure seen a year ago, when no vaccines were available.

France is the latest European country to experience a resurgence in the virus. Germany set a record this month for new cases reported in a day, and Britain is in the middle of a surge, three months after all restrictions were lifted.

The World Health Organization warned last week that Europe was back at the epicenter of the pandemic and that half a million people on the continent could die from Covid in the next few months.