Patient-reported outcomes after Tixagevimab and Cilgavimab pre-exposure prophylaxis among solid organ transplant recipients: Safety, effectiveness, and perceptions of risk

Tixagevimab/cilgavimab for the prevention of COVID-19 in solid organ transplant recipients

Tixagevimab/cilgavimab (tix/cil) received emergency use authorization in December 2021 for pre-exposure prophylaxis against COVID-19 in moderately to severely immunocompromised patients. Our study aimed to describe the incidence of COVID-19 infection and assess the immunologic risks associated with tix/cil in kidney, pancreas, liver, and heart transplant recipients. Retrospective chart review was completed to provide descriptive analysis. Outcomes data included COVID-19 infection, severity of COVID-19 infection, graft function, and rejection. Safety outcomes included cardiovascular (CV) and hypersensitivity events post tix/cil administration. A total of 410 transplant patients were included in the analysis: 20 heart, 92 liver, 243 kidney, 25 simultaneous pancreas/kidney, 23 simultaneous liver/kidney, and seven simultaneous heart/kidney. Twenty-seven (6.5%) patients tested positive for COVID-19 via PCR or antigen test post tix/cil. No apparent difference was observed in patients testing positive for COVID-19 by type of organ transplant (p = .122). Twenty-five of the 27 patients testing positive for COVID-19 reported symptomatic infection, only nine of whom were hospitalized. No patients were mechanically ventilated and no deaths due to COVID-19 occurred. No significant changes in graft function were observed. Clinically significant rejection was diagnosed and treated in four patients. COVID-19 breakthrough infection rates remained low in immunocompromised solid organ transplant recipients who received tix/cil. No significant immunologic risks were observed.

Measures to Increase Immunogenicity of SARS-CoV-2 Vaccines in Solid Organ Transplant Recipients: A Narrative Review

Purpose of review: To review the data on the immunogenicity of COVID-19 vaccines, administered by different strategies, in solid organ transplant recipients (SOTRs). Recent findings: COVID-19 booster vaccines were given to SOTRs as a widespread practice in many transplant centers, mostly as the third and/or fourth dose in an extended vaccine series, with a significantly improved humoral response compared with the initial two-dose scheme. However, one-third of SOTRs remained unresponsive, despite these boosters. Next steps: Vaccination with standard dosing remains the most feasible strategy for attaining protection against COVID-19. Additional booster doses and temporarily holding or reducing mycophenolate mofetil/mycophenolic acid may provide immunogenicity to vaccines, according to recent studies demonstrating some efficacy with these measures. Preexposure prophylaxis with monoclonal antibodies showed benefit in immunocompromised patients but is no longer recommended by the National Institutes of Health (NIH) due to diminished efficacy against Omicron and recent variants. Screening for the presence and titers of SARS-CoV-2-specific antibodies in SOTRs is not recommended in most clinical settings. T cell-based techniques are needed to evaluate vaccine efficacy and risk of infection. As SARS-CoV-2 continues to evolve, new vaccines based on conservative protein component/complexes of the COVID virus, in addition to its spike protein, are warranted to offer prolonged protection.

SARS-CoV-2 infection in high-risk children following tixagevimab-cilgavimab (Evusheld) pre-exposure prophylaxis: a single-center observational study

From 8 December 2021 to 26 January 2023, tixagevimab-cilgavimab (T-C) was authorized for pre-exposure prophylaxis of COVID-19. During this period, we used a multidisciplinary team to communicate, screen, approach, and administer T-C to eligible patients. Twenty-seven patients were eligible. Of these, 24 (88.9%) received at least one dose of T-C and three patients received two doses. Majority of patients were White, non-Hispanic, and women. Only two patients had COVID-19 prior to receiving T-C. Seventeen (70.8%) had received two or more doses of SARS-CoV-2 vaccine. No serious adverse events were noted. Seven patients developed SARS-CoV-2 infection within 180 days of receiving T-C (median 102 days; range 28-135), and only one patient developed severe COVID-19 requiring intensive mechanical ventilation in the intensive care unit.