New antibody neutralizes all SARS-CoV-2 variants

Therapeutic antibodies that previously worked early in the pandemic have become less effective as SARS-CoV-2 has mutated and evolved. In addition, newer variants, especially Omicron, have developed ways to avoid the antibodies we create in response to vaccines. However, a new, broadly neutralising antibody that could advance our capability of defending against future variants has been developed at Boston Children’s Hospital. It neutralised all currently known SARS-CoV-2 variants of concern in recent tests.
Frederick Alt, PhD, who co-led the research, has stated, “We hope that this humanized antibody will prove to be as effective at neutralizing SARS-CoV-2 in patients as it has proven to be thus far in preclinical evaluations.”
Alt and Sai Luo, PhD, used a humanized mouse model that the lab has utilised to examine for broadly neutralizing antibodies to HIV, another frequently mutating virus. The mouse models, with effectively built-in human immune systems, mimic the trial-and-error process our immune system uses to create antibodies.
The mice had two human gene segments inserted, pushing their B cells to rapidly produce a diverse range of humanised antibodies. They were then exposed to the main protein targeted by current vaccines and our antibodies from the original strain of the virus. In response, the mice produced nine lineages of humanised antibodies that bound to the spike.
The antibodies were then vetted by Alt and Luo for efficacy, it was identified that antibodies in three of the nine lineages were potent neutralizers of the original virus. In particular, the SP1-77 antibody showed very broad activity, neutralizing Delta, Gamma, Beta, Alpha, and all current and previous Omicron strains.