NEW DELHI — Two months ago, the Lok Nayak Jai Prakash Narayan Hospital in India’s capital was a battlefield. Every one of its 1,500 beds for coronavirus patients was full. It came perilously close to running out of oxygen not once, but three times.

Now, the hospital has space for every patient who needs a bed and there is oxygen to spare. Ritu Saxena, the hospital’s deputy medical superintendent, no longer spends nights fielding calls from desperate relatives. Instead, she is focused on the future: helping prepare the hospital for more surges.

“The worst is definitely over,” a relieved Saxena said.

But now India faces the challenge of trying to gain the upper hand. A resurgence of the coronavirus is feared by many public health experts if nothing is done. Key to the scramble is a renewed vaccination push and efforts to boost India’s medical infrastructure to stockpile supplies, such as oxygen cylinders, and augment care networks from city slums to far-flung villages.