Breakthrough Covid-19 cases despite tixagevimab and cilgavimab (Evusheld™) prophylaxis in kidney transplant recipients

ABSTRACT

While the combination of casirivimab-imdevimab (Ronapreve Roche Regeneron) has been shown to confer satisfactory protection against the delta variant kidney transplant recipients (KTRs) with COVID-19, it has limited neutralizing activity against the current variants of concern (Omicron BA.1, BA.1.1 and BA.2). In contrast, cilgavimab-tixagevimab combination (Evusheld, Astra Zeneca) retains a partial neutralizing activity against omicron in vitro. We examined whether preexposure prophylaxis with Evusheld can effectively protect kidney transplant recipients (KTRs) against the Omicron variant. Of the 416 KTRs who received intramuscular prophylactic injections of Evusheld (150 mg tixagevimab and 150 mg cilgavimab), 39 (9.4%) developed COVID-19. With the exception of one patient, all KTRs were symptomatic. Hospitalization and admission to an intensive care unit were required for 14 (35.9%) and three patients, respectively. Two KTRs died of COVID-19-related acute respiratory distress syndrome. SARS-CoV-2 sequencing was carried out in 15 cases (BA.1, n = 5; BA.1.1, n = 9; BA.2, n=1). Viral neutralizing activity of the serum against BA.1 variant was negative in the 12 tested patients, suggesting that this prophylaxis strategy provides insufficient protection against this variant of concern. Preexposure prophylaxis with Evusheld does not adequately protect KTRs against Omicron. Further clarification of the optimal dosing can assist in our understanding of how best to harness its protective potential.