He served there as the medical director for the Trauma and Life Support Center, in the outpatient pulmonary medicine clinic, where he performed bronchoscopic and pleural procedures.

[5][13] Early in the COVID-19 pandemic, Kory advocated for using increasing doses of corticosteroids and anticoagulants for hospitalized people with COVID-19, at a time when the general recommendation was merely for supportive care.

[10][12] Kory is president and co-founder of the Front Line COVID-19 Critical Care Alliance (FLCCC), a small U.S. organization of physicians and former journalists formed in April 2020 that advocates for ineffective COVID-19 treatments, including ivermectin.

Kory became a leading advocate of the use of ivermectin throughout the pandemic, promoting a conspiracy theory that its true effectiveness was being suppressed by the "Gods of Science" who wanted to monopolize scientific information.

The retraction was triggered when it was found the paper misreported the mortality figures of people treated for COVID-19 with the FLCCC's "MATH+" protocol, falsely making it appear to be an effective treatment.

[28][29] Kory in August 2022 falsely claimed that vaccines can disrupt pregnancy and fertility, based on his reading of Pfizer data submitted to the FDA, an interpretation which is not supported by peer-reviewed evidence.

[32] Further, according to studies cited by the CDC, there is no evidence of decreased fertility due to COVID vaccination now or in the future, and changes in menstrual cycles are small and temporary.

[34] His rhetoric carries many of the markings of conspiracy theory, which make emotional arguments that presume malfeasance and coordinated efforts and deliberate obfuscation of information.

Kory's detractors such as David Gorski[35][36] have noted his efforts to promote and profit from alternative COVID treatments are similar to medical quackery going back centuries.

[34] Effectively unable to practice within mainstream medicine, Kory launched his own “advanced COVID-19 care center", charging US$1,250 to 1,650 for a series of three appointments.