This mutation, known as E484K, is already present in both South African and Brazilian coronavirus variants. Experts believe it could have an impact on the effectiveness of some Covid-19 vaccines. Laboratory studies have shown that antibodies – which are produced by the body to counteract infection – are less able to bind to a part of the virus known as the spike protein, in order to stop it from unlocking human cells to gain entry. It was previously thought this mutation was not present in the UK variant, also known as B.1.1.7. But a recent report published by Public Health England said gene sequencing has shown that the E484K mutation has occurred spontaneously in a handful of cases (11 out of 214,159 samples) of the UK variant.