Nanobody cocktails potently neutralize SARS-CoV-2 D614G N501Y variant and protect mice

Significance Neutralizing antibodies are important for immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and as therapeutics the prevention treatment of COVID-19. We identified high-affinity nanobodies SARS-CoV-2 receptor-binding domain found that nanobody cocktails consisting two noncompeting were able to block ACE2 engagement with RBD variants present in human populations potently neutralize both wild-type N501Y D614G variant at low concentrations. Prophylactic administration reduced viral loads mice infected virus, showing useful prophylactic agents SARS-CoV-2.