Catholic leaders are encouraging people to receive Covid vaccines despite some ethical concerns regarding their creation, and fears of committing a sin by being immunised. The bishops’ conference has urged people to disregard the rumours that the AstraZeneca vaccine may have been made from aborted foetal tissue, namely the lung tissue of an aborted male foetus. However, researchers at the University of Bristol said that the aborted tissue was not part of the vaccine, but only used for testing it. While the researchers said they injected the vaccine into MRC-5 cells derived from an aborted foetus to test its effectiveness, the vaccine itself does not contain MRC-5 cells.