3-12B12-F4 for COVID-19

The COVID-19 pandemic, once a global crisis, is now largely under control, a testament to the extraordinary global efforts involving vaccination and public health measures. However, the relentless evolution of SARS-CoV-2, leading to the emergence of new variants, continues to underscore the importance of remaining vigilant and adaptable. Monoclonal antibodies (mAbs) have stood out as a powerful and immediate therapeutic response to COVID-19. Despite the success of mAbs, the evolution of SARS-CoV-2 continues to pose challenges and the available antibodies are no longer effective. New variants require the ongoing development of effective antibodies. In the present study, we describe the generation and characterization of neutralizing mAbs against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein by combining plasmid DNA and recombinant protein vaccination. By integrating genetic immunization for rapid antibody production and the potent immune stimulation enabled by protein vaccination, we produced a rich pool of antibodies, each with unique binding and neutralizing specificities, tested with the ELISA, BLI and FACS assays and the pseudovirus assay, respectively. Here, we present a panel of mAbs effective against the SARS-CoV-2 variants up to Omicron BA.1 and BA.5, with the flexibility to target emerging variants. This approach ensures the preparedness principle is in place to address SARS-CoV-2 actual and future infections.

Abstract Background Coronavirus disease 2019 (COVID-19) emerged in late December 2019 and was declared pandemic in March 2020 by the World Health Organization, causing clinically acute respiratory manifestations and corresponding symptoms, pathological inflammation and multi-organ dysfunctions. The total commitment of the scientific community to develop therapeutics to deal with this global emergency in the shortest possible period was unprecedented. In a very short time, several vaccines were approved by the EMA (European Medicines Agency) and the FDA (Food and Drug Administration). Despite this, it is conceivable that COVID-19 will continue to spread globally through evolving variants in more or less cyclic waves. With these perspectives, it is essential to quickly develop additional therapeutic tools to deal with the next wave of infection. Methods In the present study we describe the development and characterization of neutralizing mouse monoclonal antibodies (mAbs) against the receptor binding domain (RBD) of the SARS-CoV-2 Spike (S) protein. Results The mAbs identified are able to specifically detect the RBD of SARS-CoV-2 Spike protein in all tested applications, including enzyme-linked immunosorbent assay (ELISA), flow cytometry (FACS) and bio-layer interferometry. In addition, we show that these mAbs efficiently block entry of both SARS-CoV-2 pseudoparticles carrying the spike protein of the original SARS-CoV-2 strain and a broad set of variants of concern (VOC). Conclusions Here we report a panel of monoclonal antibodies that target RBD and inhibit SARS-CoV-2 variants infection and enable the isolation of novel therapeutic tools to neutralize SARS-CoV-2 virus