Introduction: Relapsing COVID-19 infections have been reported, but their etiology and severity are still unknown. In addition, there have been no cases in the literature that associate relapsing infection with immunosuppression, either from a disease course or medications.
Case presentation: This case series illustrates two patients who developed a relapsed infection, likely from recent rituximab infusions. In addition, both cases depicted a severe form of infection than the initial one. Laboratory investigations revealed these patients were unable to produce COVID-19 antibodies, even though one of the patients received convalescent plasma.
Conclusion: Clinicians should be aware of the possibility of relapsing COVID-19, especially in immunosuppressed patients. Because rituximab induces B-cell depletion, it can also decrease the effectiveness of the COVID-19 vaccine. Therefore, these patients should receive the vaccine before their scheduled rituximab infusion.