Several generations have been exposed to COVID-19 under different conditions of life at varying locations around the world. As long as the COVID-19 continues to spread, its power of genome modification would probably be increased. What concerns us more is that the 2019-nCoV, by the process of modification of genome structure, might become more and more fitted to humans to profoundly affect those who have already escaped – children and young people without a pre-existing condition. No one can tell how much time it takes to reach a new level of perfection, and that the development of vaccines for active immunization is a long process.