Effect of tixagevimab/cilgavimab for pre-exposure prophylaxis during the China Omicron outbreak

By the end of 2022, China had made a pivotal decision to optimize the COVID-19 policy. The dominant Omicron variant in China at that time was highly transmissible. In this study, we aimed to evaluate the real-world safety and efficacy of tixagevimab and cilgavimab against this background in China.

Participants were enrolled if they were over 12 years old and were planning to receive tixagevimab or cilgavimab. All participants received intramuscular administration of tixagevimab (150 mg) and cilgavimab (150 mg). Data were collected on demographics, underlying illness, prior infection, vaccination, adverse events, and COVID-19 outcomes (e.g., infection rate, hospitalization rate, and severe disease).

During the study period, 168 (37.9%) of 443 who received tixagevimab/cilgavimab were diagnosed with SARS-CoV-2 infection. All infected patients had mild COVID-19. Two patients (0.5%) were hospitalized for COVID-19, but none of them were admitted to the ICU. None of the patients died during this study. 4 (0.9%) reported mild local adverse events, and no severe systemic adverse reactions were reported.

Tixagevimab/cilgavimab may have protected high-risk populations against infection with the Omicron variant, hospitalization and severe disease during the China COVID-19 pandemic.