HLA-A and infection: On the contrary, a low incidence and mortality for Covid-19 was observed in the central-southern regions with high frequency values of the haplotype HLA-A*02:01g-B*18:01g-C*07:01g-DRB1*11:04g and of its alleles B*18:01g, C*07:01g and DRB1*11:04g in all their possible combinations containing at least one of such alleles, suggestive of potential ‘protection’ from the infection.