Gilbert, David (2021年12月20日). “A COVID-Denying Kickboxing World Champion Just Died From COVID”. Vice.com. 2022年3月21日閲覧。 “A three-time world champion kickboxer died at his home in Belgium from complications caused by COVID-19 weeks after discharging himself from the hospital. Fred Sinistra, 40, was unvaccinated and would not even use the term COVID-19. ... [He] is the latest in a long line of anti-vaccine and COVID skeptics who have died as a result of complications caused by COVID-19.”
