PARIS (AP) — During a single overnight shift this week, three new COVID-19 patients were rushed into Dr. Karim Debbat's small intensive care ward in the southern French city of Arles. It now has more virus patients than during the pandemic's first wave and is scrambling to create new ICU beds elsewhere in the hospital to accommodate the sick.

Similar scenes are playing out across France.

COVID-19 patients now occupy 40% of ICU beds in the Paris region, and more than a quarter of ICUs nationwide as weeks of growing infections among young people spread to vulnerable populations.

Despite being on...