There was a six-fold drop in the ability of antibodies from a past infection to neutralise the Delta variant of the Sars-Cov-2, and a greater eight-fold reduction in the potency of antibodies elicited by vaccines, according to a peer-reviewed study led by researchers from India and the UK. The study combines findings from lab experiments and analysis of breakthrough cases to piece together signs of the Delta variant, being better at replication and resisting antibodies. To talk more about it we're joined by one of the authors, Professor Ravi Gupta from the Cambridge Institute of Therapeutic Immunology and Infectious Disease.