evidence: In a study published June 20, 2022 in Clinical Infectious Diseases, researchers at University of California San Diego School of Medicine evaluated one such patient and found their symptom relapse was not caused by the development of resistance to the drug or impaired immunity against the virus. Rather, the COVID-19 rebound appears to have been the result of insufficient exposure to the drug. [...] The team next sampled the patient’s plasma to test their immunity against SARS-CoV-2. The patient’s antibodies were still effective at blocking the virus from entering and infecting new cells, suggesting that a lack of antibody-mediated immunity was also not the cause of the patient’s recurring symptoms. [...] This study was funded by the National Institutes of Health (grants AI036214, AI131385, CA177322, DA039562, DA046171, AI125103, K08 AI130381, DA049644, AI145555, MH128153, AI106039 and DP2 CA051915), the San Diego Center for AIDS Research (grant AI100665), the Department of Veterans Affairs, the John and Mary Tu Foundation, the James B. Pendleton Charitable Trust and the Burroughs Wellcome Fund.