Neutralizing activity against Omicron BA.5 after tixagevimab/cilgavimab administration comparable to those after Omicron BA.1/BA.2 breakthrough infections
Jinyoung Yang, Gunho Won, Jin Yang Baek, Young Ho Lee, Young Ho Lee, Haein Kim, Kyungmin Huh, Sun Young Cho, Cheol‐In Kang, Doo Ryeon Chung, Kyong Ran Peck, Kyo Won Lee, Jae Berm Park, Sang Eun Yoon, Seok Jin Kim, Won Seog Kim, Min Su Yim, Kwangwook Kim, Seokhwan Hyeon, Byung Chul Kim, Yoo-kyung Lee, Yoo-kyung Lee, Jae‐Hoon Ko
Abstract
Introduction The effect of tixagevimab/cilgavimab (Evusheld™; AstraZeneca, UK) should be evaluated in the context of concurrent outbreak situations. Methods For serologic investigation of tixagevimab/cilgavimab during the BA.5 outbreak period, sera of immunocompromised (IC) hosts sampled before and one month after tixagevimab/cilgavimab administration and those of healthcare workers (HCWs) sampled one month after a 3 rd shot of COVID-19 vaccines, five months after BA.1/BA.2 breakthrough infection (BI), and one month after BA.5 BI were investigated. Semi-quantitative anti-spike protein antibody (Sab) test and plaque reduction neutralizing test (PRNT) against BA.5 were performed. Results A total of 19 IC hosts (five received tixagevimab/cilgavimab 300 mg and 14 received 600 mg) and 41 HCWs (21 experienced BA.1/BA.2 BI and 20 experienced BA.5 BI) were evaluated. Baseline characteristics did not differ significantly between IC hosts and HCWs except for age and hypertension. Sab significantly increased after tixagevimab/cilgavimab administration (median 130.2 BAU/mL before tixagevimab/cilgavimab, 5,665.8 BAU/mL after 300 mg, and 10,217 BAU/mL after 600 mg; both P < 0.001). Sab of one month after the 3 rd shot (12,144.2 BAU/mL) or five months after BA.1/BA.2 BI (10,455.8 BAU/mL) were comparable with that of tixagevimab/cilgavimab 600 mg, while Sab of one month after BA.5 BI were significantly higher (22,216.0 BAU/mL; P < 0.001). BA.5 PRNT ND 50 significantly increased after tixagevimab/cilgavimab administration (median ND 50 29.6 before tixagevimab/cilgavimab, 170.8 after 300 mg, and 298.5 after 600 mg; both P < 0.001). The ND 50 after tixagevimab/cilgavimab 600 mg was comparable to those of five months after BA.1 BI (ND 50 200.9) while ND 50 of one month after the 3 rd shot was significantly lower (ND 50 107.6; P = 0.019). The ND 50 of one month after BA.5 BI (ND 50 1,272.5) was highest among tested groups, but statistical difference was not noticed with tixagevimab/cilgavimab 600 mg. Conclusion Tixagevimab/cilgavimab provided a comparable neutralizing activity against the BA.5 with a healthy adult population who were vaccinated with a 3 rd shot and experienced BA.1/BA.2 BI.