ABSTRACT
Neutralizing antibody (nAb) responses are attenuated in solid organ transplant recipients (SOTRs) despite severe acute respiratory syndrome-coronavirus-2 vaccination. Preexposure prophylaxis (PrEP) with the antibody combination tixagevimab and cilgavimab (T+C) might augment immunoprotection, yet in vitro activity and durability against Omicron sublineages BA.4/5 in fully vaccinated SOTRs have not been delineated. Vaccinated SOTRs, who received 300 + 300 mg T+C (ie, full dose), within a prospective observational cohort submitted pre and postinjection samples between January 31, 2022, and July 6, 2022. The peak live virus nAb was measured against Omicron sublineages (BA.1, BA.2, BA.2.12.1, and BA.4), and surrogate neutralization (percent inhibition of angiotensin-converting enzyme 2 receptor binding to full length spike, validated vs live virus) was measured out to 3 months against sublineages, including BA.4/5. With live virus testing, the proportion of SOTRs with any nAb increased against BA.2 (47%-100%; P < .01), BA.2.12.1 (27%-80%; P < .01), and BA.4 (27%-93%; P < .01), but not against BA.1 (40%-33%; P = .6). The proportion of SOTRs with surrogate neutralizing inhibition against BA.5, however, fell to 15% by 3 months. Two participants developed mild severe acute respiratory syndrome-coronavirus-2 infection during follow-up. The majority of fully vaccinated SOTRs receiving T+C PrEP achieved BA.4/5 neutralization, yet nAb activity commonly waned by 3 months postinjection. It is critical to assess the optimal dose and interval of T+C PrEP to maximize protection in a changing variant climate.
Subject(s)
COVID-19 , Transplant Recipients , Humans , Antibodies, Monoclonal , Antibodies, Neutralizing , Antibodies, ViralABSTRACT
BACKGROUND: Tixagevimab and Cilgavimab (T + C) is authorized for pre-exposure prophylaxis (PrEP) against Coronavirus Disease 2019 (COVID-19) in solid organ transplant recipients (SOTRs), yet patient-reported outcomes after injection are not well described. Furthermore, changes in risk tolerance after T + C PrEP have not been reported, of interest given uncertain activity against emerging Omicron sublineages. METHODS: Within a national prospective observational study, SOTRs who reported receiving T + C were surveyed for 3 months to ascertain: (1) local and systemic reactogenicity, (2) severe adverse events with focus on cardiovascular and alloimmune complications, and (3) breakthrough COVID-19, contextualized through (4) changes in attitudes regarding COVID-19 risk and behaviors. RESULTS: At 7 days postinjection, the most common reactions were mild fatigue (29%), headache (20%), and pain at injection sites (18%). Severe adverse events were uncommon; over 3 months of follow-up, 4/392 (1%) reported acute rejection and one (.3%) reported a myocardial infarction. Breakthrough COVID-19 occurred in 9%, 16-129 days after receiving full dose (300/300 mg) T + C, including two non-ICU hospitalizations. Most surveyed SOTRs (65%) felt T + C PrEP was likely to reduce their COVID-19 risk, and 70% reported increased willingness to engage in social activities such as visiting friends. However, few felt safe to return to in-person work (20%) or cease public mask-wearing (15%). CONCLUSIONS: In this prospective study of patient-reported outcomes, T + C was well tolerated with few serious events. Several COVID-19 breakthroughs were reported, notable as most SOTRs reported changes in risk tolerance after T + C. These results aid counseling of SOTRs regarding real-world safety and effectiveness of T + C.