Vladimir Zelenko, a self-described “simple country doctor” from upstate New York who rocketed to prominence within the early days of the Covid-19 pandemic when his controversial therapy for the coronavirus gained White House assist, died on Thursday in Dallas. He was 48.

His spouse, Rinat Zelenko, stated he died of lung most cancers at a hospital the place he was receiving therapy.

Until early 2020, Dr. Zelenko, who was additionally identified by his Hebrew identify, Zev, spent his days caring for sufferers in and round Kiryas Joel, a village of about 35,000 Hasidic Jews roughly an hour northwest of New York City.

Like many well being care suppliers, he scrambled when the coronavirus started to appear in his neighborhood. Within weeks he had landed on what he insisted was an efficient treatment: a three-drug cocktail of the antimalarial drug hydroxychloroquine, the antibiotic azithromycin and zinc sulfate.

He was not the primary doctor to advertise hydroxychloroquine. But he started to attract nationwide consideration on March 21 — two days after President Donald J. Trump first talked about the drug in a press briefing — when Dr. Zelenko posted a video to YouTube and Facebook through which he claimed a 100% success charge with the therapy. He implored Mr. Trump to undertake it.

A day later, Mark Meadows, Mr. Trump’s chief of workers, reached out to Dr. Zelenko for extra info. So did talk-show bookers. Over the following week Dr. Zelenko made the rounds on conservative media, talking on podcasts hosted by Steve Bannon and Rudolph W. Giuliani. Sean Hannity of Fox News touted his analysis throughout an interview with Vice President Mike Pence.

“At the time, it was a brand-new finding, and I viewed it like a commander in the battlefield,” Dr. Zelenko informed The New York Times. “I realized I needed to speak to the five-star general.”

On March 28, the Food and Drug Administration granted emergency authorization to docs to prescribe hydroxychloroquine and one other antimalarial drug, chloroquine, to deal with Covid. Mr. Trump known as the therapy “very effective” and probably “the biggest game changer in the history of medicine.”

But, as fellow medical professionals started to level out, Dr. Zelenko had solely his personal anecdotal proof to assist his case, and what little analysis had been performed painted a combined image.

Still, he grew to become one thing of a folks hero on the best, somebody who provided not simply hope amid the pandemic but in addition an alternative choice to the medical institution and Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, who insisted that months of analysis could be wanted to seek out an efficient therapy.

Dr. Zelenko continued to textual content and converse with Mr. Meadows, Mr. Giuliani and a number of other members of Congress. But he clashed with leaders in Kiryas Joel, who stated that his speak of treating a whole lot of Covid sufferers seemed that the neighborhood was overwhelmed by Covid, doubtlessly stoking antisemitism.

Over the following few months, researchers solid additional doubt on the efficacy of hydroxychloroquine. A research revealed in The New England Journal of Medicine discovered no profit from the therapy, and different research highlighted a threat of harmful coronary heart arrhythmias in some sufferers.

Those outcomes and others led the F.D.A. to revoke its emergency authorization on June 15, 2020.

A quiet, unassuming man, Dr. Zelenko appeared unprepared for the eye he obtained, which included harassing telephone calls and even loss of life threats. In May 2020, a federal prosecutor opened an investigation into whether or not he had falsely claimed F.D.A. approval for his analysis.

That identical month, Dr. Zelenko introduced in a video that he was closing his observe and leaving the Kiryas Joel neighborhood. He accused a number of of its leaders of instigating a marketing campaign in opposition to him.

After the F.D.A. rescinded its approval of hydroxychloroquine as a Covid therapy, he based an organization, Zelenko Labs, to advertise different nonconventional remedies for the illness, together with nutritional vitamins and quercetin, an anti-inflammatory drug.

And whereas he claimed to be apolitical, he embraced the picture of a sufferer of the institution. He based a nonprofit, the Zelenko Freedom Foundation, to press his case. In December 2020, Twitter suspended his account, stating that it had violated requirements prohibiting “platform manipulation and spam.”

Dr. Zelenko was born on Nov. 27, 1973, in Kyiv, Ukraine, and immigrated to the United States together with his household when he was 3, settling within the Sheepshead Bay part of Brooklyn.

His father, Alex, drove a taxi, and his mom, Larisa (Portnoy) Zelenko, labored in a fur manufacturing unit and later, after finding out pc programming, for Morgan Stanley.

In a memoir, “Metamorphosis” (2018), Dr. Zelenko wrote that he grew up nonreligious and entered Hofstra University as an avowed atheist.

“I enjoyed debating with people and proving to them that G-d did not exist,” he wrote. “I studied philosophy and was drawn to nihilistic thinkers such as Sartre and Nietzsche.”

But after a visit to Israel, he started to vary his thoughts. He gravitated towards Orthodox Judaism, and particularly the Chabad-Lubavitch motion.

He graduated from Hofstra in 1995 with a level in chemistry, and he obtained his medical diploma from the State University of New York at Buffalo in 2000. After returning to Brooklyn for his residency, he moved to Monroe, a city that neighbors Kiryas Joel, in 2004.

Dr. Zelenko spent three years working for Ezras Choilim, a medical middle in Monroe, and advising the native Hatzolah ambulance service. He opened his personal observe in 2007, with places of work in Monroe and Monsey, one other upstate city with a big Orthodox Jewish inhabitants.

In 2018, docs discovered a uncommon type of most cancers in his chest and, in hopes of treating it, eliminated his proper lung.

Dr. Zelenko’s first marriage led to divorce. Along together with his second spouse, he’s survived by their two youngsters, Shira and Liba; six youngsters from his first marriage, Levi Yitzchok, Esther Tova, Eta Devorah, Nochum Dovid, Shmuel Nosson Yaakov and Menachem Mendel; his dad and mom; and a brother, Ephraim.