Asthma and allergy drug montelukast can bind to and block a crucial protein produced by the Coronavirus (SARS-CoV-2), and reduce viral replication in human immune cells,  according to a new study by researchers at the Indian Institute of Science (IISc). In the study published in eLife, the researchers confirm that the drug binds strongly to one end (‘C-terminal’) of a SARS-CoV-2 protein called Nsp1, which is one of the first viral proteins unleashed inside the human cells. This protein can bind to ribosomes – the protein-making machinery – inside our immune cells and shut down the synthesis of vital proteins required by the immune system, thereby weakening it. Targeting Nsp1 could therefore reduce the damage inflicted by the virus, the study explained.