Dr. Colm Henry:

I will ask Professor Cormican, who is a viral expert, to comment on the second question. Variants of concern have a very particular definition. Mutations happen all the time in the world of virology. Many have no consequences while some do. We define variants of concern as those mutations that are associated with either increased transmissibility of the virus, increased aggressive ability to cause illness or virus resistance - a decrease in the effectiveness of public health measures, including vaccination. Of the two variants in question at this point in time, P1 and B1351 from South Africa, there is some evidence of reduced neutralising antibody response when people have been vaccinated but the vaccines are still effective to a large degree against serious illness and hospitalisation, so it is a mixed story of immunological response and ability to prevent serious illness.