Conclusion
Tixagevimab/Cilgavimab
Tixagevimab/Cilgavimab, in contrast to Regdanvimab, demonstrated higher nAbs titers to BA.1, BA.2, and BA.5 Omicron sublineages, as well as better laboratory efficacy and clinical results by Day 4 after the drug administration. The IV route of administration of Tixagevimab/Cilgavimab was associated with greater efficiency due to the faster effect. However, when compared with the nAbs titers to the Wuhan strain, a 22-fold decrease in virus-neutralizing activity was demonstrated, which suggests a possible loss of drug effectiveness due to the further mutations of SARS-CoV-2. Such rapid mutation makes it necessary to introduce new technologies into mAbs research and development.