Coronavirus (Covid-19) Do we have protection against virus infection?

Newborns have two protective systems against covid-19:
1. proteolytic system, which degrades abnormal proteins.
2. ribonucleolytic system, which degrades virus RNA.
Both systems are the most active in reticulocytes and red blood cells in newborns. If there is lack of, for instance, a proteolytic system in newborns, they could have covid-19. Infants and some adults with both active systems may have covid-19 without displaying symptoms.