Former President Pranab Mukherjee, who underwent a brain surgery on Monday, remains on ventilator support, but there has been a slight “improvement in his eyes’ reaction to light”, his daughter Sharmistha Mukherjee said on Friday. The former president, who is admitted at the Indian Army’s Research and Referral Hospital in New Delhi, was also diagnosed with the coronavirus on Monday.

The Army hospital said the former president’s condition was unchanged on Friday morning. “He is under intensive care and continues to be on ventilatory support. His vital parameters are presently stable,” a statement from the facility said, according to NDTV.

“Without getting into medical jargons, whatever I could understand from last two days is that though my dads’ condition continues to remain very critical, it hasn’t worsened,” Sharmistha Mukherjee tweeted. “There’s little improvement in his eyes’ reaction to light.”

In a separate tweet, the senior Congress leader’s daughter expressed “deepest gratitude” to people. “I strongly believe in collective energy of prayers,” she wrote in a tweet. “Deepest gratitude to all for standing by us in these difficult times. Would request to continue with your prayers.”

Pranab Mukherjee’s son Abhijit Mukherjee said that he was “responding to external stimuli and treatment”. “The 96-hour observation period ends today,” he tweeted. “My father’s vital parameters continues to remain stable and he is responding to external stimuli and treatment. My father always said ‘I got much more from people of India than I could give back’.”

On Wednesday, the hospital had said that the former president was on ventilator support and “haemodynamically stable”. The term refers to the functioning of the mechanics of blood circulation, meaning his blood flow in the heart and vessels were stable.

Pranab Mukherjee had on Monday announced on Twitter that he was infected with the coronavirus and advised all those who had come in contact with him to isolate themselves. Politicians cutting across party lines had then wished him a speedy recovery. Defence Rajnath Singh had visited him at the hospital on Monday.