Abstract
BACKGROUND: The enduring presence of COVID-19 and subsequent increasing incidence of COVID-19 reinfection has prompted evaluation of associated risk factors, particularly the role of immunosuppression. OBJECTIVE: The objective of this study was to characterize cases indicative of COVID-19 reinfection with respect to their reported use of immunosuppressant/immunomodulating agents. METHODS: This cross-sectional observational study leveraged the Pfizer global safety database (SDB) containing adverse event data collected in association with use of Pfizer products between 1 October 2019, and 30 June 2022. Selected Medical Dictionary for Drug Regulatory Activities (MedDRA(®)) Preferred Terms were used to identify COVID-19 cases; the search was further refined to comprise cases that subsequently reported events potentially indicative of COVID-19 reinfection. RESULTS: Of the cumulative total of 218,242 COVID-19 cases reported into the SDB, 4590 cases (2.1%) involving potential COVID-19 reinfection were identified. Of these 4590 cases of potential Covid-19 reinfection, a total of 134 cases reported COVID-19 specifically during treatment with pharmaceutical products, of which approximately 16% (21/134) of cases reported use of immunosuppressant/immunomodulating agents. Likewise, in the overall dataset (213,652 cases; excluding the 4590 cases involving potential COVID-19 recurrence), the percentage of reported immunosuppressant/immunomodulating agents was low (12%). In applying similar parameters to a dataset that excludes COVID-19 vaccine cases, 18% of cases reported use of immunosuppressant/immunomodulating agents (similar to the aforementioned 16% of cases reported from the overall total dataset that was inclusive of vaccine cases). CONCLUSION: This pharmacovigilance study provides a characterization of cases indicative of COVID-19 reinfection with respect to reported use of immunosuppressant/immunomodulating agents. The observations generated from this cross-sectional observational analysis may prompt further research into the role of immunosuppression in COVID-19 reinfection, in an effort to better inform clinical practice and patient management.