One of the greatest risks in the face of 2021 is the emergence of a significant coronavirus mutation, as we have been pointing out for some time. To date, there are six main known variants, two of which are especially relevant: the British and, above all, the South African strain. It is important to assess the impact that these mutations may have on transmissibility, fatality and, above all, vaccine efficacy and possible re-infection of people who have passed the common COVID-19 disease. Meanwhile, the vaccine scenario has changed in recent days, with the approval of the AstraZeneca jab by the UK