Variant-specific neutralising antibodies levels induced by the PHH-1 V SARS-CoV-2 vaccine (Bimervax®) by HIPRA

SARS-CoV-2 virus variants continue to emerge at an alarming rate due to spontaneous genetic mutations, particularly in the spike protein receptor-binding domain (RBD) portion, which render the virus more likely to escape immunity. So far, the immunity obtained through global primary and/or booster immunisation campaigns has been sufficient to protect the population from new emerging variants of the Omicron lineage. The current approach to update vaccines' antigen composition to new variants to boost immunity may not be sustainable in the long term. It might also be potentially redundant if the mutations are giving rise to variants which induce milder infections and existing vaccines, such as Bimervax®, are still sufficiently protective, as Covid is slowly becoming a seasonal illness. Through measuring neutralising antibody titres in sera from subjects boosted with Bimervax®, we have demonstrated the ability of Bimervax® to induce immune responses against a variety of SARS-CoV-2 variants, ranging from earlier variants inducing more serious infections to more recent variants which have been found to produce milder infections.