Professor Karina Butler:

The Deputy has asked a very good question but the answer is that we do not know exactly. It depends on whether the vaccines not only prevent disease and death but also prevent transmission of infection and that information just is not available yet. If they just protect the person who receives the vaccine, it will take much longer. Essentially, it will take until a large number of people are vaccinated and that will depend on the roll-out and people coming forward for vaccination. If it happens that the vaccines are very good at blocking viral turnover or replication in the nose so that it is not passed on to other people, we may see it happen sooner. It is a very good question but we do not have the answer yet.