Israel National NewsScience & TechnologyProf Risch, Dr. Zelenko challenge health officials on CovidProf Risch, Dr. Zelenko challenge health officials on CovidProfessor Harvey Risch and Dr. Vladimir Zelenko challenge the assumptions of health officials on treatment of Covid.Arutz Sheva Staff Oct 12, 2020, 9:47 AM (GMT+3)CoronavirusTrendingFound a mistake? Contact usGet the latest news in your mailbox