New target for Covid-19 vaccines identified

Next generation vaccines for Covid-19 should aim to induce an immune response against 'replication proteins', essential for the very earliest stages of the viral cycle, concludes new research carried out by UCL scientists. By designing vaccines that activate immune memory cells, known as T cells, to attack infected cells expressing this part of the virus's internal machinery, it may be possible to eliminate SARS-CoV-2 at the very outset, thereby helping stop its spread. This approach could complement currently licensed Covid-19 vaccines in the UK, which only trigger immune responses to the spike protein that protrudes from the outside of the virus. Researchers say the discovery, published in  Nature , could lead to the creation of a pan-coronaviruses vaccine, that not only protects against SARS-CoV-2 and its variants, but also against coronaviruses that cause common colds, and to new emerging animal coronaviruses. Senior author Professor Mala Maini (UCL Infection & Immunity) said: "Our research shows that individuals who naturally resisted detectable SARS-CoV-2 infection generated memory T cells that target infected cells expressing the replication proteins, part of the virus's internal machinery. "These proteins - required for the earliest stage of the virus's life cycle, as soon as it enters a cell - are common to all coronaviruses and remain 'highly conserved', so are unlikely to change or mutate.