Dr Krishan Kumar Aggarwal, a Delhi cardiologist and former chief of the Indian Medical Association who used social media with great abundance to deliver healthcare tips to the public and fellow medics, died on Monday night after Covid-19 complications. He was 62.

Dr Aggarwal, who posted video messages — including a final message that said “the show must go on” and urged doctors to offer simultaneous mass consultations — even after he was diagnosed with Covid-19, had been fully vaccinated with two doses.

Aggarwal had last year stirred ripples on social media after he borrowed terminology from yoga, physics and biology to suggest that Prime Minister Narendra Modi’s call for candles to be lit nationwide on a specific day would protect people from the coronavirus.

One of his videos posted during the epidemic had urged people to walk a circular length of 100 feet for six minutes and determine their “personal best” — whether they can walk 7, 10, or 12 or even more times that length. On developing Covid, a fall in that number would mean the lungs have been affected.

Doctors who held Aggarwal in high regard for his public outreach circulated on Tuesday what they described as his final video message in which he is seen breathing oxygen through nasal prongs.

“I’m having Covid pneumonia which is progressive, but even then, remember Raj Kapoor’s words: picture abhi baaki hai, the show must go on,” he said. “People like me will take oxygen and still take classes and try and save lives. I’m not K.K. Aggarwal, I’m the medical profession,” he had said in the video message during which he urged fellow doctors to offer simultaneous consultations to 100 patients with similar symptoms via Zoom.

“The time for one-to-one consultations is gone,” he’d said. “We have to pull people out of this crisis. Get 100 patients with similar symptoms together, give them joint consultation in 15 minutes.”

The makers of both the AstraZeneca vaccine, called Covishield in India, and Covaxin have, relying on data from their respective clinical trials, said their vaccines offer “100 per cent” protection from “severe disease”, but vaccine researchers say no vaccine is perfect.

“Exceptions do not define reality — vaccines are preventing millions of people from developing severe disease,” said Rajeev Jayadevan, a senior consultant gastroenterologist and former president of the IMA Cochin chapter. “A death is tragic, but we expect it to be exceptionally rare.”

Vaccines get approved on the basis of results from clinical trials that typically involve thousands to tens of thousands of volunteers — in the case of Covid-19 vaccines, roughly 20,000 to over 30,000 volunteers — and extreme rare responses become visible only when vaccines get used in millions of people.

In a trial involving 20,000 persons, if 20 people among 10,000 unvacccinated develop severe disease, but no inoculated volunteer develops severe disease, the protection from severe disease would be labelled as 100 per cent.

“There are individual variations in how people respond to vaccines — In some rare cases, either because of the recipient’s age, or certain underlying health conditions, full protection from severe disease may not occur,” Jayadevan said.

Aggarwal, a former national president of the IMA, the country’s largest body of doctors, had himself in a video posted on Twitter on April 28 after his Covid-19 diagnosis discussed the virtues of vaccines.

“If you have received two (doses), and if you get corona(virus), as I got it, you may have two phenomena, either significant pneumonia or significant inflammation…. I have a hyper-inflammatory response,” he had said, adding: “Don’t be afraid of vaccination. Vaccination will protect you from serious corona(virus).” J.A. Jayalal, the IMA’s current national president, said about Aggarwal: “He was a legendary leader with encyclopaedic knowledge who helped educate fellow medical professionals and the public.”

The IMA has catalogued 1,026 deaths among doctors from Covid-19 since the arrival of the epidemic — 720 during the first wave and 270 during the second wave until Monday.