India-Australia researchers predict COVID-19 vaccine efficacy

Researchers at the Indian Institute of Science (IISc) and Queensland Brain Institute (QBI) in Australia have developed a mathematical model that predicts how antibodies generated by COVID-19 vaccines confer protection against symptomatic infections. The researchers first analysed over 80 different neutralising antibodies reported to be generated after vaccination against the surface spike protein of SARSCoV-2, the virus that causes COVID-19. These antibodies are typically present in the blood for months and prevent virus entry by blocking the spike protein. The researchers hypothesised that these 80 antibodies constitute a ‘landscape’ or ‘shape space’, and each individual produces a unique ‘profile’ of antibodies which is a small, random subset of this landscape. The team then developed a mathematical model to simulate infections in a virtual patient population of about 3,500 people with different antibody profiles and to predict how many of them would be protected from symptomatic infection following vaccination.